And by the time Barnes was done for the day, he had given Farrell 3 1/3 innings and 58 pitches.
Barnes allowed five hits but no runs over his stint, walking none and striking out five.
"Just coming in, trying to throw zeros, keep the game where it was. Getting those guys a chance to go out and score some runs," said Barnes.
The Red Sox never did push many runs across, but Barnes did his job.
"I thought I had pretty good command of my fastball and I was able to mix the secondary pitches," Barnes said.
Though he came up as a starter, Barnes looks more comfortable as a reliever each time he takes the ball.
"I feel a little more comfortable now than when I first came up. It's a lot of learning the hitters, learning how to use your stuff and mixing stuff," Barnes said.
In eight games for the Red Sox this season, Barnes has a 2.25 ERA.
Ian Browne is a reporter for MLB.com. Read his blog, Brownie Points, and follow him on Twitter @IanMBrowne. This story was not subject to the approval of Major League Baseball or its clubs.