Yankees right-hander Luis Severino will leave spring training camp to return to New York for additional tests on his strained pitching forearm.

Severino already had an MRI and a CT scan that have come back negative. But manager Aaron Boone told reporters on Friday in Tampa, Fla., that Severino will begin a battery of tests on Monday.

The estimated three-day examination process is expected to include visits to multiple specialists to target the exact cause of his arm discomfort.

The forearm injury dates back to Severino's last start against the Houston Astros in Game 3 of the American League Championship Series on Oct. 15.

Boone would not say if Severino would be ready to pitch by Opening Day.

"It could be nothing and it's just a timing issue, or it could be something," Yankees general manager Brian Cashman said earlier this week.

Severino, who turned 26 on Thursday, made just three starts last season after dealing with injuries to his right rotator cuff and lat muscle. He posted a 1-1 record with a 1.50 ERA in 12.0 innings in the regular season. In the postseason, he started two games and gave up nine hits and two runs in 8 1/3 innings.

Severino earned his second straight All-Star selection in 2018, finishing 19-8 with a 3.39 ERA and 220 strikeouts in 32 starts (191 1/3 innings). He owns a 42-26 record with a 3.46 ERA in 99 career appearances (88 starts) with the Yankees.

This is the latest hit to the Yankees' rotation. Left-hander James Paxton is expected to be out until at least May after undergoing surgery to remove a cyst in his back. Domingo German is suspended until June under MLB's domestic violence policy.