ARLINGTON, Texas -- Jacob deGrom's return for the AL West-leading Texas Rangers has been pushed back until at least late June after the two-time National League Cy Young Award winner was transferred to the 60-day injured list Monday.

DeGrom hasn't pitched since April 28, when he exited early because of injury concerns for the second time in a span of three starts. He was placed on the 15-day IL the following day after an MRI showed inflammation in his right elbow.

General manager Chris Young said Monday that deGrom "hasn't improved maybe as quickly as we had hoped" after five bullpen sessions since going on the IL. Another MRI and additional testing are now planned for the 34-year-old right-hander the Rangers signed to a $185 million, five-year contract in December.

The transfer to the 60-day IL makes June 28 the earliest he could be activated.

"We don't see anything before that as a possibility," Young said. "We want to make sure that we proceed cautiously."

DeGrom was back with the team Monday after going home to Florida for the birth of his third child. He flew there after a bullpen session Wednesday in Detroit, which was his fifth since going on the IL.

Young said deGrom has dealt with some soreness during those sessions.

"There have been good days and bad, as with most recoveries," Young said. "I don't know specifically how he felt in the bullpen [in Detroit]. I heard the ball was coming out well. ... Honestly, he's going through a life moment at home, and this is one we didn't call checking in every hour to see how he was doing."

The Rangers signed deGrom in free agency after he had played his first nine big league seasons with the New York Mets. He was limited by injuries to 156 1/3 innings over 26 starts his last two years in New York.

He had a career-low 1.08 ERA over 92 innings during the 2021 season before missing the final three months with right forearm tightness and a sprained elbow. He didn't make his first big league start last year until Aug. 2 after being shut down late in spring training because of a stress reaction in his right scapula.

Texas has won all six games started by deGrom (2-0), but the right-hander has pitched only 30 1/3 innings. He has a 2.67 ERA with 45 strikeouts and four walks. He threw 3 2/3 scoreless innings against the New York Yankees on April 28 before leaving that game because of discomfort in his arm.

"I believe he's the best in the world when he's pitching. ... It's just captivating when he's on the mound," Young said. "But the decision to bring him here was a five-year decision, and we're taking that into consideration in terms of how we're proceeding here."

DeGrom wasn't in the clubhouse before the series opener against the St. Louis Cardinals, which was before the Rangers announced the change in his status.

"He's so happy for the team and the way we've played. But he wants to be a part of it. He wants to be out there," said Young, a former big league pitcher. "I've been in his shoes, so I understand how it goes. And you want to push to be out there, but you don't want to push at the risk of making things worse or having setbacks or anything like that."

Transferring deGrom to the 60-day IL opened a spot on the Rangers' 40-man roster to activate Spencer Howard from the 60-day IL. Howard missed the first 58 games because of a right lat strain.