BOSTON -- Right fielder Shane Victorino reinjured his back while taking a check swing in the sixth inning of Wednesday's 6-5 win against the Athletics. After grounding out to short in that same at-bat, Victorino jogged ever so lightly to first base.
Victorino, who missed Boston's day-night doubleheader on Sunday with lower back tightness, didn't take the field when the seventh inning started.
Manager John Farrell is confident that the injury is minor and will pass within a day or two.
"His back tightened up again in the last at-bat. Not as severe as the last time when he missed the game," said Farrell. "We took him out for precautionary reasons. We'll check him again tomorrow. But a smart move on his part, when he felt it, to just shut it down at that point."
When the Red Sox went out for defense in the seventh, Daniel Nava moved from left field to right field. Mike Carp took over in left and moved into Victorino's No. 2 spot in the batting order.
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.