And the Red Sox also needed the hard-throwing righty after a tough loss by the bullpen on Friday and two key relievers (Joe Kelly and Robbie Ross Jr.) still out sick.
Barnes earned the win in relief of Rick Porcello, bridging the gap to closer Craig Kimbrel by allowing one hit and no runs while striking out three.
"It was tough driving back [Saturday] to Boston and then having to get on a plane," said Barnes. "I'll be honest, it was one of the last things that I wanted to do was to get on a plane and go flying after three-and-a-half hours at my grandma's funeral [Saturday] morning.
"But it's great to be back with the team. This is kind of one of those things, when you're going through something that's difficult, it's almost nice to get back to a normal schedule as much as you can. That doesn't help you forget it, but it kind of helps ease the pain a little bit with it."
At a time bullpen roles are very much in question for the Red Sox, the opening is there for Barnes to emerge as the primary setup man.
"Coming down toward the end of the game, I'll absolutely be ready for that," said Barnes. "But if there is a situation that arises in the fifth, sixth, seventh, and that's where they feel I'm best used to help the team win that day, I'll be ready for that. My routine's not going to change. I stretch in the fifth inning every game no matter what. So [I'll] be ready for any and all things."
Barnes stayed ready for Sunday's assignment by playing catch at Fenway on Thursday and then throwing with his cousin before Saturday's funeral in New York.
And when manager John Farrell put Barnes into a one-run game -- the Red Sox were trailing, 4-3 -- he was sharp from the outset.
"Yeah, two key innings to get that power arm back," said Farrell. "He's throwing a lot of strikes. Just to add 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."
Ian Browne has covered the Red Sox for MLB.com since 2002. Follow him on Twitter @IanMBrowne and Facebook. This story was not subject to the approval of Major League Baseball or its clubs.