Orioles left-handed reliever Troy Patton is heading to the 15-day disabled listed after spraining his right ankle as he was walking in the parking garage of his hotel Sunday night.

Patton said X-rays on the ankle were negative, but he has been wearing a large boot since the injury and has had to use crutches for going long distances. He expected to be ready to return once he’s eligible to come of the DL on Aug. 28.

“I just kind of caught the edge wrong and rolled my ankle,” Patton said. “It’s the third time I’ve done it to this ankle, so I think it happened pretty easily.”

Newly acquired left-handed reliever J.C. Romero will be the team's only left hander in the bullpen tonight. Right-hander Steve Johnson has also been called up and will likely be available for long relief behind left-handed starter Wei-Yin Chen.

The 26-year-old Patton is having his best major league season, going 1-0 with a 2.58 ERA and 48 strikeouts and 43 hits in 52 1/3 innings. He's held left-handed batters to a .204 batting average.

“It’s extremely frustrating, very, very, very frustrating,” Patton said. “I haven’t felt this good as I’ve felt on the mound in my whole career so it’s very frustrating.

“It’s frustrating for this team and this situation we’re in facing lineups with heavy left-handed hitting lineups,” Patton added. “I would be used a lot in the next few days. I fell irresponsible that I put the team in this situation.”