Mariners 2021-22 Free Agent target: Marcus Semien

Of all the spicy Hot Stove rumors that have been floating around, one that seems to get persistent play is the Mariners’ interest in Marcus Semien. The surface appeal is obvious: Semien, a California native, reportedly prefers either to re-sign with Toronto or go to a team on the West Coast; and he’s the most obvious candidate among the monster free agent shortstop class to switch to second base full-time, something that’s important as Jerry Dipoto made it clear in some recent comments that J.P. Crawford will be the team’s shortstop moving forward.

John, ever the hipster, made a pitch last off-season that the Mariners should sign Semien when Oakland, presaging the teardown that looms ahead this off-season, failed to bring him back, crying poor to MLB agents who came sniffing around the Coliseum. In hindsight, it was a particularly damning indictment of the direction Oakland’s franchise was about to take, as the A’s knew better than anyone else what they had in their homegrown star, who struggled early with defense at shortstop before righting the ship in 2018, and whose bat was similarly slow to warm to MLB pitching as a hit-over-power infielder who was too often missing the hit until an electric 2019.

As it was, Semien’s market was a slow, strange one: dogged by questions about his defensive abilities and whether or not his 2019 offensive performance was a juiced-ball fluke after a down 2020. He lingered on the market longer than a player a year removed from a 33-home run season should have, until Toronto eventually scooped him up for a relatively modest $18M one-year contract, causing John to virtually wad up his article and hurl it like a discus in the direction of T-Mobile Park.

In response, Semien was an MVP-caliber player for Toronto, contributing 45 home runs, Gold Glove defense at second base, and bringing his trademark durability to a team that struggled, like most other teams in MLB this season, with injuries. Since making it to the majors in 2015, Semien has had fewer than 600 plate appearances twice: in 2017, when he had wrist surgery, and in the pandemic-shortened 2020 season, when he also missed about a week of games dealing with some left side soreness. Off the field, Semien also contributed veteran leadership, spending time with shortstop Bo Bichette and sharing things he wished he had known sooner, making such an impression on Bichette that the young shortstop teared up speaking about what Semien’s influence meant to him in a post-season presser.

That performance wasn’t any surprise to John, who noted in his article that Semien has had the traits of a good hitter for years, just without the production one might expect from a player who controls the zone as well as he does. It’s very difficult to get Semien to chase, and he’s good at hitting high fastballs (he slugged over .600 on fastballs in the top third of the zone in 2021), so pitchers routinely work the bottom of the zone against him. In 2020, Semien repeatedly popped the ball up (16% IFFB rate, almost double MLB average), especially on breaking balls or off-speed pitches. In 2021, with no change in his average launch angle (in fact, a slight increase), Semien’s infield fly ball rate regressed to norm, while an increase in hard contact (back to career norms of 36% after a down 28% in 2020) helped send more of those balls out rather than just up. Undoubtedly, Semien was also aided by playing in the Baby’s First Ballparks of the AL East and Toronto’s temporary home in Buffalo, but he hit almost an exact equal number of his home runs at home (22) and away (23) this season. In fact, if Semien played all his games at T-Mobile Park, he actually would have added two extra home runs to his season total. There are only other two other parks in the league where he’d beat that total, and one of them is in Houston, where Statcast predicts Semien would have ripped 54 dingers into those dumb Crawford Boxes. (For that alone, I would like him to be a Mariner. Also, retroactive thanks to Semien for getting Joe Smith traded to the Mariners, where he helped out in the bullpen quite a bit.)

Defensively, Semien answered any questions about how he’d fare at second base definitively, winning the first Golden Glove of his career. He ranked in the 88th percentile among second basemen for Outs Above Average, committing just eight errors in his first full-time season at the position. Seattle fans have seen Mariners infield coaching legend Perry Hill transform a talented-but-inconsistent shortstop in J.P. Crawford into one of the best defensive shortstops in the league, in addition to making the more lead-footed Ty France into a Gold Glove candidate at first if not for a stupid innings requirement. Semien is older than those two but more towards the natural athletic talent of Crawford on the defensive spectrum, and it’s reasonable to expect him to maintain or even improve his production under the watchful eye of the Gold Glove-maker Hill. It’s also important not to lose sight of the fact that Semien is just a year removed from playing a very good defensive shortstop. Semien could also either help spell J.P. at short or, in the event of disaster, take over at the position, allowing Seattle to address a more easily-fillable hole at second base instead.

Semien was a key piece in the Blue Jays’ run towards the playoffs, and the Rogers-funded Canada’s Team will try hard to re-sign him, as there’s no rehabbing player returning to take the spot or top prospect ready to promote from the minors. (Toronto reportedly already attempted to sign Semien to an extension during the 2020 season, but he rejected it.) West Coast preference or not, there’s an undeniable appeal for Semien to return and finish what the 2020 Blue Jays started, although Toronto has to do some serious upgrading to their pitching staff to make that happen, something they may try to accomplish through trades. It’s annoying to think about the fact that, if it had been Seattle to give Semien a relatively modest $18M, not only would they have enjoyed his production all season, but they’d also be the ones in the catbird seat right now encouraging him to return to a familiar, friendly environment.

Any team courting Semien, though, should be ready to finally pay him in line with his production of the past two full seasons, both offensively and defensively. Most outlets project a four- or five- year deal for Semien, at anywhere between $100-$120M dollars. Some have attempted to use the deal the similarly-aged DJ LeMahieu (6 years/$90M) signed with the Yankees after the 2020 season as a framework for Semien, although it should be noted that deal was signed after the pandemic-shortened season in an off-season where most clubs, including the Mariners, were reluctant to loosen the purse strings. For the Mariners, who still don’t have much in the way of infield prospects on the rise (Noelvi Marte notwithstanding), a lengthier deal shouldn’t be an issue and could give the Mariners an advantage over other clubs who want to offer a higher AAV but for fewer years. However, the Mariners also have deep pockets and one of the league’s lowest payrolls, and should be able to match, dollar-wise, anything another club could offer. Either way, the Mariners have the flexibility to get a deal done with Semien, should he want to return to the AL West, and the opportunity to make up for what they missed out on last season.