What would a Marcus Semien contract extension cost?

One of the Oakland A’s biggest storylines this offseason has been the future of Marcus Semien. The star shortstop is coming off a breakout 2019 season that saw him place third in AL MVP voting, but 2020 will be his final year of arbitration before he can hit the open market as a free agent after the season.

We already know that both sides have interest in working out an extension before the end of next season. But last Monday, Jon Heyman of MLB Network provided an update:

There isn’t a ton here we didn’t already know, but one of the main takeaways is the current focus on his upcoming arbitration, which would suggest no long-term deal is imminent. Also important, though, is Semien’s continued interest in working out a deal — talks have been slow, but there are no indications they have stalled or soured in any way.

The A’s want to keep Semien around; that’s a given. They have some shortstop prospects in the system, but nobody that’s a sure bet to be ready for a win-now 2021 team. But as usual, money is going to be the issue. Semien’s insane 2019 season may have priced him out of Oakland.

At Baseball Trade Values, Semien’s surplus trade value for 2020 is calculated to be $38.0M — that is, his $51.5M adjusted field value less his projected $13.5M arbitration figure. And going forward, he projects to be an incredibly valuable player.

These values come with the important caveat that they will be impacted significantly by his 2020 performance, and how well he follows up last year’s breakout. Additionally, as Semien ages, he could be forced to move to second base — which would hurt his value — but this potential position switch is not factored into these values. Still, these projections serve as a decent ballpark figure for how productive he will be over the next six seasons.

This isn’t to say that a deal will cost the A’s $25M+ per year, either. Players don’t tend to receive full market value on extensions, and if anyone is going to give his team a hometown discount, it’s Semien. As Heyman noted, he’s a Bay Area native and has much to owe the team for sticking with him through the rough start to his major league career.

Conveniently, another shortstop in a very similar situation to Semien’s received a significant contract extension just last spring — Boston Red Sox All-Star Xander Bogaerts. Also entering his final year of team control, Bogaerts agreed to a six-year, $120M extension with an opt-out after three years. After factoring in his 2019 arbitration salary of $12M, that’s seven years and $132M, for an average annual value of just under $19M.

There are some significant differences between the two that need to be taken into account. Bogaerts’ contract extends Boston’s control through his age 27-32 seasons, while a Semien extension would begin after he turns 30. Bogaerts was also a more established player, with three seasons of 4.0 or more fWAR under his belt at the time of signing, compared to Semien’s one. However, Semien’s 2019 was almost three wins better than Bogaerts’ best year.

With all of that taken into consideration, here’s my best estimate of what a Semien extension could look like:

Since the 2017-18 offseason, only four free agent hitters over the age of 30 have received contracts of four years or longer — catcher Yasmani Grandal (four years, entering 2020), designated hitter J.D. Martinez (five years, 2018), and outfielders Lorenzo Cain (five years, 2018) and A.J. Pollock (five years, 2019). Semien is coming off the best season of the four by far, but doesn’t have anywhere near their long-term track records, so I don’t think he can reasonably expect a contract to take him through his age-34 season.

However, this deal would line up quite nicely with the one Bogaerts got. He’d get a $3.5M raise over his 2019 arbitration estimate, and including the buyout on his 2025 team option and a possible signing bonus, the deal would come out to about $100M over five years. Semien doesn’t quite get the years or AAV that Bogaerts did since age is not on his side, but he still does very well for a player going into his 30s, especially considering the struggles similar players have seen on the open market in recent years.

Maybe Semien pushes for that extra guaranteed year, or his agent wants to beat Bogaerts’ AAV. There’s some wiggle room there; to me, this just looks like a fair framework for a deal that the A’s and Semien could agree to. But that leads to an even more important question: should the A’s make this deal?

Payroll is already looking tight in 2020, even after the A’s shed the pricey arbitration contracts of Blake Treinen, Jurickson Profar, Josh Phegley, and Ryan Buchter. It doesn’t get much better in 2021 — Khris Davis is still locked in at $16.75M while stars Matt Chapman, Matt Olson, and Frankie Montas enter their first year of arbitration, and Sean Manaea and Mark Canha hit their third time through. They’ll lose veterans Joakim Soria, Yusmeiro Petit, and Liam Hendriks to free agency, but likely need to use the money freed up by them to spend on their replacements. Davis comes off the books after 2021, but the aforementioned arb-eligible players will only be getting more expensive quickly, and they’ll be joined by Ramon Laureano.

So with future payroll looking questionable at best and a level of uncertainty still surrounding new ballpark plans, is committing nearly $20M per year to a 30+ year-old shortstop really the best use of Oakland’s limited resources?

I’d say no. The A’s don’t have a clear replacement for Semien waiting in the wings, but they still have time. He isn’t likely to repeat his insane 2019 season, and there’s a decent chance he’d accept the qualifying offer after 2020 and return for 2021. In those two seasons, maybe a youngster like Nick Allen, Logan Davidson, or Jorge Mateo shows that they’re ready to take over, or maybe Semien even settles in as a more modest 3-4 win player that could be locked up on a more affordable contract.

In a perfect world, the A’s hand each of Semien, Chapman, and Olson a blank check and let them finish their careers with the team that took them to stardom. But that isn’t happening. Tough decisions will need to be made, and while Semien is an excellent player in his prime coming off a phenomenal year, Chapman and Olson might be the better long-term franchise building blocks. The Matts, both two-way stars already in their mid-20s, are probably the smarter investment, even if it means saying goodbye to one of the best stories in baseball sooner than the team is ready to.

I still think there’s a chance the two sides work a deal out. After all, projection too far into the future could be dangerous. The A’s are competitive right now, and who knows if they still will be when Chapman and Olson are nearing free agency. Oakland could decide it’s safer to keep this core intact while it’s clearly working and worry about tomorrow’s problems, well, tomorrow.

But a Semien deal won’t be cheap. It could have a negative impact on the future payroll and the team’s ability to retain its other stars. I’d never say never when it comes to Oakland’s front office, but when it comes to a Semien extension, I wouldn’t hold my breath.