Lewis went on the disabled list with forearm tendinitis in June, received an anti-inflammatory injection and returned to the rotation three weeks later without making a rehab appearance. He lasted five innings at Oakland last Wednesday before complaining of renewed soreness in the forearm.
After giving it a couple more days of rest and seeing no improvement, Lewis met with team orthopedist Keith Meister to discuss options. Lewis can be a free agent after 2012, which further complicates matters. He still opted to undergo surgery rather than try to pitch until the tear became complete.
"I didn't want to have one pitch where everything went 'pop,' and I started to practice my golf game," Lewis said. "It's devastating. It's another speed bump in my career."
Lewis missed most of the 2004 and 2005 seasons after rotator cuff surgery.
Rangers general manager Jon Daniels acknowledged that the team will look options on the trade market leading up to next week's deadline. Milwaukee, which has right-hander Zack Greinke to deal, had a pair of scouts at the Rangers' 9-1 win over the Boston Red Sox on Monday. The Rangers also had a scout at the Miami Marlins-Atlanta Braves game on Monday to watch Miami right-hander Josh Johnson.
In the meantime, 21-year-old rookie left-hander Martin Perez will fill Lewis' rotation spot, beginning Tuesday against Boston. Perez, who was recalled from the minors Monday, was 1-1 with a 5.54 ERA in four games (two starts) for Texas earlier this season. He was 5-5 with a 4.59 ERA in 16 games (15 starts) for Class AAA Round Rock.