"It wasn't anything drastic," Weaver said, "but just something me and [Angels manager Mike Scioscia] thought it would be better to iron out now than toward the end of the season."
The Angels have an off-day on Thursday, so Garrett Richards could pitch on Friday against the Mariners on regular rest instead of Weaver. Against the Yankees from June 29-July 1, Scioscia said he has some options to replace Weaver, including Nick Tropeano, Cory Rasmus and Jose Alvarez.
Weaver doesn't know when he'll return. He'll have tests Monday to determine the severity of the injury.
He said he experienced periodic sharp pains during Saturday's start. The hip would loosen up and he would feel fine, but then it would tighten up again.
"Pitchers are always trying to perform with little nicks, and Weav has," Scioscia said. "I think it just got to a point in his last couple starts where you see mechanically he's not where he wants to be."
Weaver hopes the time off gives him a chance to return to the way he pitched in May, when he posted a 4-1 record and 2.83 ERA.
"Go on the DL and get this figured out and move on and come back and be strong again," Weaver said.
• Scioscia managed his 2,500th regular-season game on Sunday. Does he have another 2,500 games in him?
"Let's worry about today's game," he said.
• A's speedster Billy Burns entered Sunday's game with five infield hits in two games during the series against the Angels.
"Our guys are shallow and trying to take some of the holes away that our spray charts are showing, but he's found some holes," Scioscia said.
• Second baseman Johnny Giavotella hit leadoff for the Angels, and David Freese was back in the lineup batting fifth and playing third.