Here's the 411 on Polar Bear's contract

This story was excerpted from Anthony DiComo's Mets Beat newsletter. To read the full newsletter, click here. And subscribe to get it regularly in your inbox.

In terms of news value, the contract that Pete Alonso agreed to on Thursday hardly caused a stir in the baseball universe -- and rightfully so. Eligible for salary arbitration for the third and final time, Alonso had minimal leverage in negotiating a one-year, $20.5 million deal. A bigger payday is destined for next winter, when Alonso can be a free agent for the first time.

• Another one! Vladi Guerrero signs with Mets

Understanding that MLB’s compensation system can be confusing, I wanted to use today’s newsletter to break down exactly where things stand on Alonso, his contract and a potential extension, answering some of the more common questions I’ve heard along the way.

What exactly did Alonso agree to last week?
Baseball’s basic salary structure has three tiers. Players with fewer than three years of MLB service time have few rights when it comes to their salaries. As such, almost all of them make the Major League minimum or close to it. Players with at least six years of service time have the right to free agency and can negotiate with any team. That’s why their contracts tend to be large.

Then there are the tweeners, the players with at least three years of service time but fewer than six. That group is arbitration-eligible, which gives them the right to earn salaries based on past precedent. Teams and players use historical comps to draw up salary figures, and typically aren’t far apart with their estimates. When the system works, as it did with Alonso on Thursday, deals tend to happen quickly.

If teams and players can’t agree, they exchange their proposed salary numbers and go to a hearing, where an independent arbiter listens to arguments and chooses one salary figure or the other. This can be a contentious process that both sides strive to avoid, so it’s good news that the Mets were able to do so with Alonso.

What does this have to do with an extension?
Not all that much. The Mets had to go through this process with Alonso (and six others on their roster) regardless of their future plans.

That being said, the arbitration process does tend to spur conversation between teams and players, opening what can generally be referred to as extension season. The bulk of long-term extension agreements tend to happen between January and Opening Day. Although no one from the Mets’ camp or Alonso’s has ruled out the idea of negotiating during the season, it’s relatively rare for a big extension to happen midsummer.

So what are Alonso’s chances of an extension?
Whenever they’ve been asked over the past year, Alonso and Mets officials have delivered some version of the same message: Alonso loves being in New York, the Mets love having him, but let’s just wait and see what happens. The most likely outcome has always been Alonso testing free agency next November. That’s not something Steve Cohen’s Mets fear, because if they still want to lock up Alonso to a long-term deal at that time, they have the financial muscle to outbid anyone (plus the emotional advantage of being the only franchise Alonso has known).

While it’s possible the Mets extend Alonso before then, it doesn’t seem likely. The team has little incentive to take on the added risk of locking him up a year early, while Alonso has lots of incentive to bet on himself, put together a monster 2024 and cash in next winter.

Does the fact that Alonso hired Scott Boras to represent him change anything?
Not really. One of Boras’ hallmarks is encouraging players to wait for free agency before signing a contract, but Alonso was likely to do that even before changing agents.

Mets fans shouldn’t fear the idea of Boras. While baseball’s most famous agent rightfully has a reputation as a hardline negotiator, he also has a lengthy history of re-signing players to their previous franchises. Brandon Nimmo was an example of that last winter.

What about the possibility of a trade?
Considering the forcefulness with which Mets president of baseball operations David Stearns has said he won’t trade Alonso this winter, there’s no reason to think he’s being anything but honest. Of greater question is the 2024 Trade Deadline, which will be full of Alonso rumors if the Mets fall out of contention.

On that front, Stearns has guaranteed nothing. Given such uncertainty, the Mets probably will touch base with Alonso at some point over the next six months to gauge whether they can re-sign him. If they think he’s going to bolt in free agency, they may look to move him rather than risk letting him leave for nothing.

But as we sit here today, it’s difficult for me to consider a trade of Alonso all that likely, even in July. Stearns and Cohen know how unpopular it would be. They also have to believe they’ll be the heavy favorites to re-sign Alonso in free agency. Unless the relationship deteriorates significantly between now and midseason, it’s reasonable to think Alonso will remain a Met at least for the duration of the summer, and quite possibly for many years to come.