Keller (back) threw two shutout innings for short-season West Viriginia on Monday. He allowed one hit while striking out four batters, DK Pittsburgh Sports reports.
The outing was Keller's first since May 16, when he left his start for High-A Bradenton with lower back pain. "It was pretty frustrating," Keller said of his injury. "I just kind of did it in the bullpen warming up. It's just frustrating because it wasn't even during the game." The righty, who threw 21 of 30 pitches for strikes Monday, said he'll make another start for West Virginia on Saturday.