In a perfect world, the Red Sox could have waited a couple of days to see if Napoli would need a DL stint. But things are imperfect for a team that has lost nine game in a row, including a 15-inning crusher Saturday.
Boston needed to open up a roster spot for Sunday's starting pitcher -- righty Brandon Workman.
The original plan was that righty Alex Wilson would be optioned back to Triple-A Pawtucket. But given the workload of the bullpen Saturday, and in recent days, manager John Farrell needed to keep Wilson for at least another day.
"And hopefully this gives Mike that extended period of time to get past this in its entirety or at least try to get further ahead of it," said Farrell. "And we needed to keep the backup infielder with Xander [Bogaerts] coming out of [Saturday's] ballgame as well."
Bogaerts exited Saturday's game with cramping in his right hamstring, but was back in the lineup on Sunday.
For the two-game series in Atlanta that starts Monday, David Ortiz will start at least one game at first base as the Red Sox lose the designated hitter. Mike Carp will be the primary first baseman during Napoli's time on the disabled list.
Napoli hasn't hit for much power since the injury, hitting .238 with two homers, 13 RBIs and a .366 slugging percentage.
In 43 games this season, he's hitting .260 with five home runs, nine doubles and 22 RBIs. Napoli leads the Red Sox with a .390 on-base percentage and 31 walks.
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.