DETROIT -- Matt Barnes didn't get to watch much of the implosion of the Red Sox bullpen on Friday at Comerica Park. Barnes was in upstate New York, having skipped the first two games in Detroit to be with his family for his grandmother's funeral on Saturday morning. He watched most of the game on his iPad, he said, but had turned it off before Heath Hembree, Robby Scott and Joe Kelly frittered away what should have been an uplifting come-from-behind win.

Neither Hembree nor Scott nor Kelly pitched after Boston again rallied against the Detroit bullpen on Sunday, taking a lead in the late innings. Barnes ensured they didn't have to. In doing so, he cemented his place as Boston's primary setup reliever -- certainly while offseason acquisition Tyler Thornburg is out with a shoulder injury, perhaps even after Thornburg returns.

Barnes struck out three in two emphatic innings of relief behind Rick Porcello on Sunday, stranding one inherited runner and then stranding another runner in scoring position an inning later. The best pitch he threw was a hammer of a full-count curveball he dropped on Victor Martinez after three straight fastballs. He has struck out five and walked one in 3 2/3 innings pitched in three appearances, and he hasn't been charged with an earned run.

"A guy that's maybe a little bit more seasoned than some others in some of those big spots, he's going to be a pivotal guy in our bullpen," Farrell said.

Barnes didn't get to throw much while he was away from the Red Sox for three days. He worked out and played catch at Fenway Park on Thursday, the day the Boston-Pittsburgh series finale was washed out, and then he played catch with a cousin in New York on Saturday before he drove back to Boston.

It was the return to the Red Sox and the return to his routine that helped Barnes get past the loss of his grandmother.

"That doesn't help you forget it," he said, "but it helps ease the pain a little bit with it."

In terms of being prepared to pitch, the biggest advantage Barnes had from being away was that he'd been away from the clubhouse through which flu has been sweeping -- claiming Kelly as its latest victim on Saturday.

But Barnes would have been the choice over Kelly on Sunday no matter what. He has thrown strikes. Kelly has not. He said his role doesn't matter -- he'll stretch in the fifth inning no matter what -- but it's becoming clear what his role is.

"I feel like my mechanics are in sync right now, staying through the ball," Barnes said. "I'm commanding stuff really well right now. I feel ready."