One 92.3 mph sinker may have wrecked Boston’s postseason plans. Jakob Junis drilled Willson Contreras on the right hand near the knuckle on September 17, and the Red Sox have not had their biggest power threat in the lineup since. Contreras leads Boston with 27 home runs, but with the Wild Card series approaching, the Red Sox could be forced into October without the hitter they can least afford to lose. There is also an uncomfortable wrinkle to the injury: Contreras crowds the plate, which has become part of the discussion around why he gets hit so often.

“This is a huge problem for the Red Sox if Willson Contreras can’t be in the lineup. This is not a team that relies on power, but everybody does have their own role, and Willson Contreras is the power provider in this lineup,” an MLB analyst said via MLB Network.

Contreras is not just another bat in Boston’s lineup. He is the bat. He is hitting .276 with a .905 OPS, 27 home runs and 81 RBI, while Wilyer Abreu has 24 homers and Jarren Duran has 20. No other Red Sox hitter has reached the 20-home-run mark this season. Boston’s offense has also struggled to consistently generate runs down the stretch, making Contreras’ absence even harder to absorb.

The alternatives do not offer the same kind of power. Nick Sogard is hitting .267 with four home runs in 191 at-bats this season, while Curtis Mead’s Red Sox tenure was interrupted almost immediately when he suffered a left wrist fracture after being hit by a pitch in his Boston debut. Neither gives Boston a like-for-like replacement for Contreras’ production.

Contreras himself knows how uncertain the situation is. “I’m working hard with the trainers; the hand is slowly getting better,” he said Thursday night, per MLB.com. “But I haven’t been able to swing the last two days. I’ll be honest with the team. I know Tuesday is a really important game. It’s a really important series, and I’ll be completely honest with the team.”

The good news is that X-rays showed no fracture. Contreras was diagnosed with a badly bruised knuckle between his right ring finger and pinkie, along with swelling and soreness. Interim manager Chad Tracy said the pitch caught Contreras on his top hand as he turned through, which helps explain why the injury is such a concern for his swing. MLB later reported that Contreras had been able to grip a bat and take some swings, but his availability for the postseason remained uncertain.

There is also an uncomfortable debate over how he got here. Contreras stands close to the plate, and MLB Network panelists pointed directly to that tendency while discussing the injury. “We were just talking about how close he stands to the plate,” they said.

Contreras himself has pushed back on the idea that his stance fully explains why he gets hit. “A lot of people might say that I hit on top of the plate,” he said after the injury. “They don’t get hit like me.” Junis also apologized afterward, with Contreras acknowledging that the pitcher was simply trying to work inside.

That makes the situation more complicated than simply blaming Contreras for crowding the plate. His stance may reduce the margin for error on inside pitches, but Contreras clearly believes there is more to the frequency with which he has been hit.

The Yankees have their own major injury question. Aaron Judge is on the injured list with a right calf strain, and his availability for a potential Wild Card series remains uncertain. Yankees manager Aaron Boone has declined to give a timetable, while Judge has said returning for the postseason is still his plan.

So this could become a postseason matchup in which one or both teams are missing their biggest power threat. For Boston, though, there is no pretending Contreras is easy to replace. If he cannot swing comfortably, the Red Sox are not just losing another hitter. They are losing the player who has supplied more home-run power than anyone else in their lineup this season.