Jason Vargas will undergo surgery Wednesday to remove a blood clot from his left armpit area, a procedure that is expected to sideline the Angels left-hander for three weeks to a month.

Vargas, who was put on the disabled list Friday with a 6-4 record and 3.65 earned-run average in 14 starts, will not throw for at least two weeks. Once he resumes throwing, he should have enough arm strength to return after a few bullpen sessions and a minor league start or two.

"We're all relieved this was caught, not for a guy coming back to pitch but for a guy needing a procedure for a condition that could be very serious," Manager Mike Scioscia said. "This needs to be taken care of. That's the most important thing."

Vargas could be a prime target of contenders looking to acquire pitching before the July 31 trade deadline, and the blood clot could hamper efforts to trade him for prospects who could bolster a weak farm system. But Vargas should have a few starts before the end of July to prove he is sound.

Thumbs up

An MRI test revealed no structural damage in the left thumb of Peter Bourjos, which the center fielder jammed sliding into second on Sunday. Bourjos, who was diagnosed with a bruise, entered the game in the eighth inning Tuesday night as a replacement for Mike Trout in center field, and he could start on Wednesday.

"I was really relieved," Bourjos, said before the game. He missed 40 games in May and June because of a left hamstring strain and is batting .331 with a .386 on-base percentage in 35 games.

"I was pretty nervous. When I woke up Monday, it was probably twice the size it is now and black and blue in the area where a lot of guys tear the ligament. But the swelling has gone down a lot since yesterday."