The Texas Rangers have promoted top pitching prospect Martin Perez, recalling the left-hander from Triple-A Round Rock on Tuesday.

The Rangers signed Perez, 21, as a free agent out of Venezuela in 2007. He entered this season as Texas' third highest-rated prospect and No. 31 overall, according to Baseball America.

"I've been working hard, and it's finally paying off for me," Perez said. "I was called up here to help the team as much as I can."

Perez is 5-5 with a 4.59 ERA in 15 starts for Round Rock this season but has pitched much better of late. He registered one of his best starts of the season this past Thursday, going nine innings and allowing two runs on three hits. He walked two, struck out four and needed just 90 pitches in the complete game.

In his start before that, Perez tossed seven shutout innings, allowing one hit while striking out five.

Rangers general Jon Daniels said Perez has earned the chance.

"He's throwing a lot of strikes, really attacking the zone," Daniels said. "He's being very aggressive. Where we feel he is right now, if the can continue on that same path, we feel he's got a chance to help us."

The pitching-thin Rangers bypassed Perez earlier this month because he had been struggling with his fastball command, opting instead for right-hander Justin Grimm.