What to expect from Triston Casas

The future of Boston’s first-base position is arriving in the Fens.

The Red Sox have called up Triston Casas, MLB Pipeline’s No. 26 overall prospect, to join the Major League club Sunday. The move comes when rosters have been expanded to 28 players for September, and with 4 1/2 weeks remaining on the Major League calendar, Casas will likely retain his rookie status for 2023 without surpassing the 45-day or 130-at-bat thresholds.

The 22-year-old first baseman joins the big club at a productive and healthy time.

Casas missed almost two months with a right ankle injury in the middle of the season. Since returning to Triple-A Worcester on July 22, he had produced a .296/.404/.504 line with five homers over 36 games before receiving this weekend’s big call. The left-handed slugger had slashed .248/.359/.457 in 36 games through the first two months of the season prior to the injury, signaling just how much he had adjusted to Triple-A pitching over the second half of the campaign.

He leaves the WooSox with a 127 wRC+ on the season, fourth-best among the 14 Triple-A players aged 22 or young with at least 250 plate appearances at the level. Gunnar Henderson (138), Mark Vientos (131) and Miguel Vargas (129) were the only eligible players ranked higher in the category. Henderson and Vargas are fellow September callups.

Drafted 26th overall by Boston in 2018, Casas hasn’t needed much time to prove his capabilities at the plate with an OPS above .820 at every full-season Minor League stop. His approach has long been lauded by Red Sox officials for the way he controls the strike zone and keeps his strikeout rates in check. He also shows a willingness to spray the ball to all fields with authority; only 39 percent of his batted balls were pulled at Worcester this season.

That said, he does exhibit plus-plus raw power -- he had become well-accustomed to moonshots over the Worcester Wall in Polar Park’s right field -- and had been working on tapping into it more in games in recent seasons. That will continue to be a focus in the Majors, even with the deeper right field at Fenway, and Casas is certainly capable of hitting 30-plus homers at his peak in The Show.

On the defensive side, Casas was drafted as a third baseman but shifted across the diamond after a thumb injury cut his debut Minor League season short in 2018. Despite his size at 6-foot-4, he has kept his nimbleness that pays off on quick reaction plays, and his soft hands are certainly useful on hops and scoops at first. He also retains a plus arm from his high school pitching days that comes in handy on double plays or throws across the diamond.

At the least, Casas should be a defensive improvement over the rotating cast of Bobby Dalbec, Franchy Cordero and Christian Arroyo that Boston has used at first base lately, and he should continue to get looks there when veteran trade acquisition Eric Hosmer returns from his back injury. Red Sox first basemen collectively ranked 28th in the Majors with -10 Outs Above Average and 30th with -11 Defensive Runs Saved entering Saturday.

Manager Alex Cora and the Sox may also choose to ease Casas in with a focus on facing right-handed pitching early in his Major League career. The club’s No. 2 prospect slashed .289/.392/.553 in 237 plate appearances against Triple-A righties this season, but managed just a .224/.350/.269 line in 80 plate appearances against lefties at the same level. Those splits have been consistent for much of Casas’ time in the upper Minors and will be worth following as he takes his first Major League hacks.

The Red Sox have held out hope that Casas would be the organization’s first baseman of the future, joining Xander Bogaerts and Rafael Devers as homegrown All-Star infielders. That future becomes the present Sunday.