Source: Rangers eye Rick Porcello

The Texas Rangers, still trying to determine a No. 5 starter for their rotation, inquired Monday about Detroit Tigers right-hander Rick Porcello, a source told ESPNNewYork.com's Adam Rubin.

On Sunday, two Rangers pitchers in contention for the spot each had outings to forget.

Justin Grimm, a 24-year-old right-hander, had his second consecutive poor start, allowing six runs on six hits in 2 1/3 innings. Martin Perez, a 21-year-old left-hander, entered the game in the fifth inning. He walked the first two batters in the sixth and then was hit on the forearm by a line drive. X-rays revealed a fracture of the ulna that will sideline him for at least four weeks.

Porcello, 24, was 10-12 with a 4.59 ERA for the Tigers in 2012. He has a 48-42 record in four seasons with Detroit.