Yankees pitcher Luis Severino throws in the bullpen during spring training in...

Yankees pitcher Luis Severino throws in the bullpen during spring training in Tampa, Fla., on Feb. 16, 2020. Credit: Newsday/J. Conrad Williams Jr.

DETROIT — Luis Severino could be a week or so away from officially starting his rehab clock.

That means he will be closer to returning to a Yankees rotation that certainly could use him. He could be back within four to six weeks from the time that clock begins.

Aaron Boone said Sunday that Severino, recovering from the Tommy John surgery he had in late February 2020, is a candidate to start a rehab assignment "potentially as early as the end of next week," likely with Class A Tampa.

Boone said "today or tomorrow," Severino is slated to pitch a three-inning simulated game.

"Basically, he’s on a six-day rotation right now," Boone said.

Meaning, with no setbacks from the simulated game, he would start a rehab assignment by week’s end.

Severino is the process of building up his arm strength — going through essentially a full spring training — hence the possibility of a return in the range of four to six weeks.

Kluber update

Boone said the Yankees should get further clarification on Corey Kluber’s prognosis in the coming days.

Kluber, diagnosed last Wednesday with a subscapularis strain in his right shoulder and shut down from throwing for at least the next four weeks, has been gathering "some second and third opinions and stuff" since that diagnosis, Boone said Sunday.

"Still working to get our arms around exactly what we’re dealing with," Boone said. "We should have a good idea, hopefully by Tuesday or Wednesday, about what exactly we think we’re dealing with and what the steps forward are from there."

Boone: Gittens on Yankees’ radar

With first baseman Luke Voit out at least a month — and likely longer — with a Grade 2 right oblique strain and the Yankees getting little production from the position overall, Boone said the Yankees have taken notice of Chris Gittens and his start with Triple-A Scranton/Wilkes-Barre.

Going into Sunday, the 27-year-old Gittens, who is not on the 40-man roster, was hitting .268 with four homers and a 1.098 OPS.

"He’s very much on our radar," Boone said.

One rival scout who covers the Yankees' minor league system said Gittens has earned a chance.

"Bat definitely looks real," the scout said. "I’d give him a shot [in the majors]. And [he] can’t be worse than what they’ve been getting there."

Extra bases

The Yankees transferred Aaron Hicks, who opted to have season-ending surgery to repair a torn tendon sheath in his left wrist, to the 60-day injured list … The club signed lefthander Nestor Cortes Jr. to a major-league contract and added him to the 26-man roster from Triple-A Scranton/Wilkes-Barre. After relieving starter Michael King in Sunday's 6-2 loss to the Tigers, Cortes allowed two runs (one earned), three hits and four walks in 3 2/3 innings. He struck out three.

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