BOSTON – Injuries have become an all-too-recurring theme for the Red Sox in September, and another one cropped up on Friday when the surging suffered a right biceps injury that could knock him out of the playoffs.

“At this point, it looks like a significant biceps injury, so he's going to still be seeing more doctors and stuff like that,” said manager Chad Tracy. “We'll get the final conclusion, but it's a pretty significant biceps injury. It's probably going to take him out.”

Gasper suffered the injury while striking out in the fifth inning of the 4-3 win over the Cubs in Game 1 of a split doubleheader at Fenway Park. When Gasper struck out on a sweeper by Clay Holmes, he immediately started flexing his right arm.

For weeks, there has been a debate if Gasper’s recent power tear would land him a starting spot against righties in the postseason.

But that debate appears to be off the table entirely, increasing the likelihood the Sox play Jarren Duran in left field against righties with Roman Anthony at DH. Anthony will play left against lefties, with Jahmai Jones likely to serve as the DH.

It was a rough way for Gasper’s season to end.

Ten of Gasper’s 12 career homers have come in his last 33 games, starting on Aug. 17. He has a 1.082 OPS over that span, covering 106 plate appearances.

It has been a heartwarming rise for the 30-year-old Gasper, a journeyman who spent part of eight seasons in the Minor Leagues.

Creating additional concern for the Red Sox is that Willson Contreras is still not certain to be back for the postseason due to a right hand injury sustained on Sept. 24.

Gasper, who can also catch, would have been an option to replace Contreras. All the Sox can hope is that Contreras doesn’t need to be replaced.

“Any time there's an injury and you got stuff going on, it creates uncertainty,” said Tracy. “Obviously we're pushing, and our hope is we get [Contreras] in there, but that creates uncertainty for sure. But as we've done most of the year, whatever actually ends up being the case with all of that, we plan to go play [good] baseball because that's what we’ve been doing all year.”