Red Sox reliever Ryan Brasier, left, has been optioned to Triple-A. LM Otero/Associated Press

BOSTON — The Red Sox have optioned reliever Ryan Brasier to Triple-A Worcester to make room on the active roster for Michael Wacha.

Wacha, who was on the 15-day injured list with left intercostal irritation, will start Friday here at Fenway Park against the Mariners.

Brasier has allowed five home runs in 14 1/3 innings this season. He gave up a home run in the ninth inning Thursday.

The righty has a 6.28 ERA, 1.47 WHIP and .316 batting average against in 18 outings for Boston this season.

What do the Red Sox want him to work on at Worcester?

“Mix up his pitches, get the fastball up in the zone, keep working on his slider,” Red Sox Manager Alex Cora said. “It’s one of those, it’s not an easy decision with what he means to us. But in the end, he knows he has to get better and he will.”

Brasier has posted a 3.67 ERA in 159 outing (149 2/3 innings) for the Red Sox since 2018.

RED SOX PROSPECT Connor Seabold was scheduled to start for Triple-A Worcester on Friday but he has been scratched because of a pectoral strain.

“It’s kind of like what happened with Whit (Garrett Whitlock) last year,” Red Sox manager Alex Cora said. “So we shut him down. We’ll see how it progresses in the upcoming days and we’ll go from there.”

Whitlock spent time on the IL late last season with right pectoral tightness.

The Red Sox don’t view it as anything serious right now for Seabold.

“As of now, not yet,” Cora said. “Not yet.”

Seabold is one of Boston’s top depth starters. The 26-year-old righty, who is on the 40-man roster, has gone 3-1 with a 2.45 ERA, 0.93 WHIP and .179 batting average against in seven starts for Worcester this year.

He last pitched Sunday vs. Rochester when he struck out 11 in 6 scoreless innings. He allowed just one hit and one walk.