Friday marks one of the most important dates on baseball’s offseason calendar, though it has nothing to do with the glut of big-name free agents still available.

Players eligible for salary arbitration and their teams must either settle on a contract for 2021 (or agree to a multiyear deal) by 1 p.m. ET today, or exchange salary figures for the upcoming season.

More than 100 arbitration-eligible players remained unsigned, as of Thursday. And while teams and players can still negotiate up until their arbitration hearing, it has become more common for the two sides to simply head to arbitration if they can’t reach a deal before the submission deadline. With that in mind, here the storylines to watch ahead of Friday’s deadline.

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How will the shortened 2020 season impact arbitration?
This is the biggest issue surrounding arbitration cases this year, as Major League Baseball and the MLB Players Association never came to a formal agreement on how to handle the valuation of a 60-game season.

Simply put, this will be an arbitration season like we’ve never seen before.

We’ve already seen a number of “pre-tender” deals signed before last month's tender deadline, as player agents and teams alike compromised in the interest of avoiding a potential hearing. Many industry insiders expect a large number of settlements by Friday because teams and agents could be hesitant to spend the money required to go to a hearing.

The deals signed to this point appear to involve middle ground between treating 2020 as a traditional season and a 60-game sprint. How those deals look after Friday will be interesting, as will the number of players who actually get to the point of exchanging salary figures with their teams.

Will Josh Hader and the Brewers have another standoff?
Reliever Josh Hader’s case was one of the most compelling last year; the left-hander filed for $6.4 million, and the Brewers filed at $4.1 million. Despite winning back-to-back National League Reliever of the Year Awards in 2018 and ’19, Hader lost his case. The Brewers argued that he shouldn’t be paid as a top closer, given that he hadn’t held that traditional role for the majority of his first three years in the Majors.

Well, Hader was most certainly Milwaukee’s closer in 2020, leading the NL with 13 saves. Following last year’s battle, will the two sides come to a deal before exchanging figures, or will Hader try to right what he perceived as a wrong a year ago?

The Top 10
Of the 10 biggest one-year contracts ever given to arbitration-eligible players, nine have been signed during the past three years. Last year, Mookie Betts, Kris Bryant, Francisco Lindor and Trevor Bauer joined the list. (Betts was already on there, giving him two of the top deals of all time.)

Mookie Betts: $27 million (2020)
Nolan Arenado: $26 million (2019)
Josh Donaldson: $23 million (2018)
Bryce Harper: $21.625 million (2018)
Mookie Betts: $20 million (2019)
David Price: $19.75 million (2015)
Anthony Rendon: $18.8 million (2019)
Kris Bryant: $18.6 million (2020)
Francisco Lindor: $17.5 million (2020)
Trevor Bauer: $17.5 million (2020)

Will any players crack the Top 10 this year? Lindor and Bryant figure to beat their own numbers, which would add their new deals to the list.

Aside from those two, no other players figure to land deals worth at least $17.5 million. Cody Bellinger, who set a first-year arbitration record last year with an $11.5 million settlement with the Dodgers, seems unlikely to top Betts’ $20 million second-year record from 2019.

Will the Mets and Francisco Lindor get an extension done before exchanging salaries?
When the Mets acquired Lindor in a blockbuster trade last week, the speculation began immediately about when the two would hammer out a long-term extension.

It feels likely that such a deal will happen, possibly before the start of the 2021 season, but it doesn’t have to happen by Friday. Lindor said he is open to signing an extension, though he doesn’t want to negotiate once the season gets underway. That would leave an artificial deadline of Opening Day, giving the two sides more than two months to work out a deal.

Two years ago, Arenado and the Rockies agreed to a $26 million deal for 2019, an arbitration record at the time. Roughly six weeks later, the two sides agreed to an eight-year, $260 million deal that began in 2019, replacing the one-year pact he had signed. Should Lindor and the Mets reach just a one-year deal on Friday -- or even exchange salary figures -- it is unlikely to impact the prospect of a long-term deal.

Corey Seager and the shortstops
Aside from Lindor, there are four other shortstops whose cases will be closely watched on Friday.

The Dodgers’ Corey Seager may have had the best overall season of any arbitration-eligible player, finishing in the Top 10 of NL MVP Award voting while picking up MVP Awards for both the NL Championship Series and World Series.

Seager’s injury-riddled 2018 season cost him greatly in his first year of arbitration. A pair of All-Star seasons in 2016 and ’17 and an NL Rookie of the Year Award put him on track to challenge first-year arbitration records, but a platform year that saw him limited to 26 games resulted in a $4 million salary for ’19.

A solid 2019 season helped Seager earn a raise to $7.6 million last season. Although many players will be hurt by the 60-game shortened season, Seager’s postseason heroics should give him a strong case for a sizeable raise.

Lindor, the Cubs' Javier Báez, the Astros' Carlos Correa and the Nationals' Trea Turner are also third-year eligibles this year. (All can become free agents at the end of the season, except for Turner, who has a fourth year of arbitration eligibility in 2022.) The Rockies' Trevor Story, another All-Star shortstop headed for free agency at the end of this season, signed a two-year, $27.5 million deal in January 2020, avoiding his final year of arbitration.

How will the shortened season impact their 2021 salaries, and perhaps more important, what will these negotiations mean for these players and their teams in terms of their relationships going forward?

Making their first pitch
There are five pitchers in position to potentially set new marks for first-time arbitration-eligible hurlers without a Cy Young Award: Cardinals right-hander Jack Flaherty, Dodgers righty Walker Buehler, White Sox righty Lucas Giolito, Reds righty Luis Castillo and Braves lefty Max Fried.

Dallas Keuchel has the record for a first-time arbitration-eligible pitcher, receiving $7.25 million in 2016 after winning the 2015 American League Cy Young Award.

For first-year eligible pitchers who didn't yet have a Cy Young Award in their trophy case, David Price and Jered Weaver hold the record at $4.365 million, including bonuses earned, followed by Dontrelle Willis and Shelby Miller at $4.35 million. It should be noted that both Luis Severino and Aaron Nola would have eclipsed these marks, as the Yankees ($4.4 million) and Phillies ($4.5 million) each filed record numbers before agreeing to long-term deals with the pitchers.

(Also of note: Even if a player sets a new arbitration record of any kind this year, those numbers will be ineligible to be used in any future arbitration-related comparisons, per last March’s agreement between MLB and the MLBPA, rendering these figures less important than in a typical year.)

How these five pitchers fare following the shortened season should be interesting to monitor.

The Boras factor
Agent Scott Boras has three notable clients in their first year of arbitration-eligibility: Nationals outfielder Juan Soto, A's third baseman Matt Chapman and Phillies first baseman Rhys Hoskins.

Last August, Boras argued that future compensation for players should not be reduced because of the shortened 2020 season, suggesting that multipliers should be used to project what full-season statistics would have looked like.

Given his first-time arbitration client list, it’s easy to see why he would want that system imposed. But with no formal agreement on how to evaluate the value of a shortened season, there’s no reason to think that teams will view the situation that way.

Sources say that clubs are essentially saying, “Here’s what this player did in 60 games, and this is what 60 games is worth.” With that in mind, will Soto, who posted monster numbers during his 47 games in 2020, be compensated in the range of the top first-year eligible players ever?

Chapman is in an even shakier position after injuries limited him to 37 games. As previously noted, Seager’s injury-shortened 2018 season cost him millions in his first year of arbitration despite his strong performance during his first two seasons. Chapman may find himself in a similar scenario this year.

Four players in recent years have exceeded $10 million in their first year of eligibility: Bellinger, Bryant, Lindor and Betts. Yankees outfielder Aaron Judge received $8.5 million last year, falling short of the eight-figure mark despite a strong start to his career.

Chapman would have been on track to join the $10 million club had 2020 been a season in line with his first two. Soto might have had a similar case, as well.

Boras has a recent history of avoiding arbitration hearings for his clients. He has gone to a hearing just three times since 2009. (Weaver lost his case in 2011, while Pedro Álvarez and Gerrit Cole won their cases in '15 and '19, respectively). Expect that trend to continue, with Soto, Chapman and Hoskins agreeing to deals to avoid a hearing.

Big-market intrigue
The Yankees and Dodgers are among the most interesting clubs to watch this week, but for different reasons.

New York has eight unsigned arbitration-eligible players, including two-thirds of its potential starting lineup: Judge, Luke Voit, Gleyber Torres, Gio Urshela, Gary Sánchez and Clint Frazier.

Torres and Voit are both first-year eligibles, though their cases trend in different directions. Torres posted a pair of All-Star seasons in his first two years, but struggled in 2020. Voit had solid stretches before 2020, then led the Major Leagues with 22 home runs during the shortened season. The two players should find themselves in similar salary territory when all is said and done, though it will be notable to see how this year’s arbitration market impacts them.

As for the Dodgers, they took a hard line a year ago, exchanging numbers with four players -- more than any other club. Two of them (Max Muncy and Chris Taylor) signed multiyear deals before going to a hearing, but the Dodgers went to a pair of hearings, beating outfielder Joc Pederson and losing to reliever Pedro Báez.

Will the Dodgers take a similar stance this year, or will their first World Series title since 1988 cause them to loosen the purse strings?

While most players around the league had just 60 games to play in 2020, the Dodgers played 18 more in October -- an additional 30%. How will those extra opportunities help Dodgers players as they make their cases? Seager and left-hander Julio Urías had huge postseasons. Buehler, who made just eight starts in the regular season, posted a 1.80 ERA in five postseason starts.