One contract extension candidate for each club

Free-agent season is already a blast, and it's just getting started. But it's worth noting that some of the best players never reach free agency at all. In fact, if teams have their way, most of them won't.
The point for teams of extending players before they reach free agency is to keep their cost down before those players hit the open market. The point for players to sign an extension early is receiving the security of a long-term contract years before free agency happens. Extensions, in an ideal world, can work for everybody.
With that in mind, we look at the best extension candidate for every MLB team. Not all of these players will necessarily take an extension; some will want to go the Bryce Harper and Manny Machado route and trust their skills to take them to the open market. But some are ideal fits, and we look at one for each club. (Note: All ages listed are a player's seasonal age; how old they will be on July 1 of next season.)
AMERICAN LEAGUE EAST
Blue Jays: Randal Grichuk, OF, age 27
Free agent after … 2020 season
Grichuk actually led Toronto with 25 homers last year and is an above-average defensive outfielder. He has two years of arbitration left. Maybe the Blue Jays should buy out those two and add another year to get him into his 30s?
Orioles: Dylan Bundy, RHP, age 26
Free agent after ... 2021 season
Bundy has a great arm, even if last season was a rough one. But if the Orioles think he can be a part of their next winning team, he's young enough to nail down now and will likely be the cheapest he'll ever cost.

Rays: Willy Adames, SS, age 23
Free agent after ... 2024 season
Assuming Blake Snell will want to ride his AL Cy Young Award when he hits the free-agent market after the '22 season, how about Adames? He's 22 years old, showed he's a big leaguer last season and plays a premium position. Can they extend him in a similar manner to how they did Evan Longoria in 2008?
Red Sox: Mookie Betts RF, age 26
Free agent after ... 2020 season
He now has an AL MVP Award. He loves playing in Boston. He is absolutely beloved by Boston fans. He's only 26 years old. He's got two years left of arbitration. Now might be the best time to get it done.
Yankees: Aaron Hicks, CF, age 29
Free agent after ... 2019 season
Hicks has one year left on his current deal, but he might desire long-term security more than, say, fellow pending free agent Didi Gregorius.
AL CENTRAL
Indians: Francisco Lindor, SS, age 25
Free agent after ... 2021 season
Cleveland has certainly triedto extend Lindor, but it should keep trying. Because no one represents the Indians more, or better, than Lindor.

Royals: Whit Merrifield 2B, age 30
Free agent after ... 2022 season
Merrifield has plenty of arbitration years left. But the Royals can potentially get him some security at a cheap price and, theoretically, have a substantial trade chip if they need it.
Tigers: Jeimer Candelario, 3B, age 25
Free agent after ... 2023 season
The Tigers have no obvious extension candidates, considering Michael Fulmer is probably considered more trade bait if he gets healthy than an extension candidate. The Tigers have a long road back.
Twins: José Berríos, RHP, age 25
Free agent after ... 2022 season
Berrios has a new agent that some speculate was hired for just this reason.
White Sox: Omar Narváez, C, age 27
Free agent after ... 2022 season
Narvaez was quietly one of the better catchers in the AL last year. Could the White Sox commit to him as their guy to transition into the next generation?
AL WEST
Angels: Mike Trout, CF, age 27
Free agent after ... 2020 season
Well, it can't hurt to ask.

Astros: Alex Bregman, 3B, age 25
Free agent after ... 2022 season
The Astros are not going to be able to extend all of their young stars, so it's time to make some decisions. Bregman is as good a place as any to start.
Athletics: Matt Chapman, 3B, age 26
Free agent after ... 2023 season 
The A's didn't make a lot of headway trying to extend Chapman last offseason, and it'll be more expensive to do it now. They should still try.
Mariners: Mallex Smith, OF, age 26
Free agent after ... 2022 season
Now that the Mariners traded for Smith (again), he's maybe not the worst guy to commit to over the next five years or so during what is surely going to be a period of much transition.
Rangers: Joey Gallo LF, age 25
Free agent after ... 2022 season
There aren't a lot of players like Gallo in baseball, for better and worse. He is still so young that maybe the Rangers will bet on improvement all around.
NATIONAL LEAGUE EAST
Braves: Ronald Acuña Jr., LF, age 21
Free agent after ... 2024 season
It will never be too early to talk extension with the game's next superstar.
Marlins: Lewis Brinson CF, age 25
Free agent after ... 2023 season
Last season was enough of a step back for Brinson that the Marlins might get a discount on, if they believe the talent is still all there.
Mets: Jacob deGrom, RHP, age 31
Free agent after ... 2020 season
deGrom does know the Mets' GM pretty well, at least.

Nationals: Anthony Rendon, 3B, age 29
Free agent after ... 2019 season
Rendon only has one year left on his current deal, but there is no obvious replacement for him at third base in Washington. Maybe the Nats respond to theoretically losing Harper by extending Rendon?
Phillies: Aaron Nola, RHP, age 26
Free agent after ... 2021 season
Now is probably the ideal time to extend Nola. If the Phillies are so willing to spend, spending in-house on their ace is a terrific place to start.
NL CENTRAL
Brewers: Josh Hader, LHP, age 25
Free agent after ... 2023 season
It's a risk to extend any reliever, but we've seen how important Hader is to the Brewers.
Cardinals: Jack Flaherty, RHP, age 23
Free agent after ... 2023 season
Of all their young pitchers, the Cardinals see Flaherty as the one leading their rotation into the next decade.
Cubs: Javier Báez, INF, age 26
Free agent after ... 2021 season
If Kris Bryantisn't interested in signing a long-term extension with the Cubs, maybe last year's NL MVP Award finalist would be?

Pirates: Francisco Cervelli, C, age 33
Free agent after ... 2019 season
The Pirates' last extension with Cervelli worked out magnificently. Perhaps they're up for another one?
Reds: José Peraza, SS, age 25
Free agent after ... 2022 season
The Reds may be extensioned-out for a while, but Peraza took some steps forward last year.
NL WEST
D-backs: David Peralta LF, age 31
Free agent after ... 2020 season
Depending on what direction the D-backs go, Peralta is a short-term extension fit … unless everyone else starts leaving.
Dodgers: Corey Seager, SS, age 25
Free agent after ... 2021 season
Whether extension talks with Seager really get going may depend on what free-agent moves, if any, the Dodgers make this offseason.
Giants: Madison Bumgarner LHP, age 28
Free agent after ... 2019 season
There have been some recent trade rumors relating to Bumgarner, but he should really be a Giant for the rest of his career.
Padres: Manuel Margot, CF, age 24
Free agent after ... 2022 season
Unless the Padres want to talk to Fernando Tatis Jr. about an extension already, they should lock up Margot. 
Rockies: Nolan Arenado 3B, age 28
Free agent after ... 2019 season
It is possible Arenado and the Rockies will be all we're talking about this July.