Wakefield was scheduled to pitch on Tuesday night against the Rangers. Instead, the Red Sox will call up a pitcher from the Minor Leagues to pitch that night, and Wakefield will be placed on the 15-day disabled list.
Manager Terry Francona said the hope is that the right-hander will miss just two starts.
The injury is similar to the one that bothered Wakefield late last season, keeping him off the roster for both the American League Division Series and the World Series. The tightness Wakefield is experiencing is in the back of the shoulder.
By taking quick action now, the Red Sox are hopeful Wakefield can have a strong finish to the season.
"I talked to [Red Sox medical director] Tom Gill yesterday," said Francona. "We think that if we act now, this will be favorable. Because again, he's been pitching great. That's why it's hard. You want to leave him out there, because he's pitching so well."
Despite a 7-8 record, Wakefield is turning in one of his most consistent seasons, as evidenced by his 3.67 ERA. He leads the Red Sox with 15 quality starts.
The injury explains why Wakefield was removed following just 81 pitches in his last start, against the Royals.
"Remember, I said I was kind of trying to protect him," said Francona. "He was getting stiffer and stiffer as the game progressed. It was getting harder to get loose. He was still throwing great, which has been hard, kind of hard to put it together, because he's been so effective. He went out to throw his side [session] yesterday and really had a tough time. So we all sat down and thought, because of what we went through last year, we got to a point where we kind of got in no-man's-land.
"Let's send him back, let him get a cortisone shot, let Tom Gill examine him and the hope would be he'd miss two starts and come back for the remainder of the season, be able to pitch the way he can pitch."
The top three candidates to replace Wakefield on Tuesday appear to be Michael Bowden, Devern Hansack and another knuckleballer, Charlie Zink.
Bowden is one of Boston's top pitching prospects, and is supposed to pitch for Pawtucket on Monday. Hansack, who has served several stints with the Sox, last pitched on Aug. 7. In terms of numbers, Zink (13-4, 2.89 ERA) is probably most deserving, but he would have to make the start on three days' rest.
Ian Browne is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.