HOUSTON (CBSNewYork/AP) — New York Yankees ace Luis Severino is returning to New York to have more tests on his injured right shoulder.

Yankees manager Aaron Boone says Severino isn’t where he wants to be and the team wants an examination to determine why he isn’t progressing as expected. Severino was supposed to start on opening day but has been out since he was scratched with right shoulder inflammation from what would have been his first spring training appearance on March 5.

Boone said before New York opened a series at Houston on Monday that Severino will fly to New York on Monday night, will see head team physician Dr. Christopher Ahmad and have an MRI and possibly other tests on Tuesday.

Boone said: “I’m hoping that it’s just him not quite being able to get over the hump yet. The original testing that we did with him led us to be pretty confident. But we’ve got to make sure that he’s right and the fact that he hasn’t been able to graduate from the flat ground throwing yet to the mound, we’ve got to try and answers those questions as best we can.”

The right-hander played long toss on Saturday and felt fine but Boone says he “didn’t feel as great” on Monday after playing catch, which led to the decision to send him for more testing.

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