PITTSBURGH -- Jacob deGrom threw a 32-pitch bullpen session Monday before the Texas Rangers played the Pittsburgh Pirates as the right-hander continues his recovery from elbow inflammation.

"It went really, really well," Rangers manager Bruce Bochy said. "He said he feels great and didn't feel anything at all there."

DeGrom threw all fastballs. He will add breaking balls to the mix when he throws his next bullpen Friday, when the Rangers play at Baltimore.

Bochy said no timetable has been established for deGrom's return, and that the 34-year-old could possibly be added to the active roster without a minor league rehab assignment. There is a possibility that he throws again Friday in Baltimore.

"He will start spinning it now," Bochy said.

DeGrom has been on the 15-day injured list since April 29. That was a day after he departed early for the second time in his last three starts, and an MRI showed some inflammation.

Texas has won all six games started by deGrom (2-0), but he has been limited to 30⅓ innings. He has a 2.67 ERA with 45 strikeouts and four walks.

DeGrom played his first nine big league seasons with the New York Mets. He was limited to 156⅓ innings over 26 starts the past two years because of injuries before signing his $185 million, five-year deal in free agency in December.

The Associated Press contributed to this report.