The Angels are officially holding their breath. Shohei Ohtani is headed to the disabled list, and his return date is unknown.

The two-way star was shelved on Friday with a grade 2 sprain of the UCL in his right pitching elbow, the team announced. For now, the Angels hope to avoid him having to go under the knife. He will be evaluated in three weeks after getting a PRP and stem-cell injection on Thursday in Los Angeles.

Ohtani left after four innings on Wednesday against the Royals due to a blister on his right hand that previously was an issue for him in April. He complained about the elbow being stiff after the blister was drained, leading to an MRI, general manager Billy Eppler told Angels reporters.

Whether Ohtani can avoid Tommy John surgery, which is sometimes needed for severe UCL injuries, Eppler said: “We’re hopeful that he can, that it is completely treatable with the biologic prescription the doctors recommended.”

It is uncertain if he could go back to merely hitting after he is evaluated in three weeks. Shortly after Ohtani signed with the Angels in December, Yahoo Sports reported he had a first-degree sprain of the UCL in his elbow.

Following an underwhelming spring training, Ohtani has more than lived up to the hype that accompanied his move to MLB from Japan this offseason, shining on the mound and in the batter’s box. The 23-year-old right-hander is 4-1 with with a 3.10 ERA and 61 strikeouts in 49 1/3 innings pitched. As a designated hitter, Ohtani has posted a stellar .289/.372/.535 slash line with a .907 OPS, six home runs and 20 RBIs in 114 at-bats.

He’s been a major factor in the Angels’ bounce-back season so far, after the club finished under .500 a year ago. But before this recent four-game winning streak, they had struggled of late, falling 4 1/2 games behind the surprising Mariners in the AL West. And now they have a doubly devastating hole to fill on their roster for the time being.