CLEVELAND >> The Twins, in short order, are preparing to welcome back Royce Lewis and Willi Castro. Simultaneously, it seems as if they’ll play all of May without two players that likely would have been key contributors.

Luke Keaschall, who suffered a non-displaced fracture of his right ulna, and Matt Wallner, who suffered what head athletic trainer Nick Paparesta described as a “moderate to severe hamstring strain,” will both have extended absences.

Keaschall, who suffered the break Friday when he was hit by a pitch, has gotten multiple opinions. At this point, the Twins do not believe he needs surgery. But healing a bone isn’t a quick process, and the Twins do not expect to have an update on Keaschall, who is wearing a soft splint right now, for another month.

As for Wallner, Paparesta said his injury was a Grade 2 or 3 strain. Lewis, for reference, had what the Twins called a moderate strain and his absence will top six weeks, making it likely that Wallner’s would be of similar length, which would take him out of play for May.

“He has never had a leg injury before in his life. Didn’t know what was going it on,” Paparesta said. “He thought he had a cramp. … Two days later it looks black and blue, and it’s a pretty significant tear.”

The outfielder started jogging on Monday for the first time since suffering the injury last week. He has been playing some light catch but has yet to start hitting, and Paparesta will have another evaluation with him again when the Twins return home.

On the bright side for the Twins, Lewis and Castro (oblique) are nearing their returns.

Castro has been making strides, participating in a range of baseball activities including infield work and outfield work, throwing and running. The switch hitter hit from the right side on Monday, though that wasn’t the side giving him trouble. Tuesday, he’ll start to get in some left-handed swings, which will provide a better indicator of his readiness.

And Lewis is in the middle of a rehab assignment that will now shift from St. Paul to Columbus, Ohio.

The Saints begin a series in Columbus on Tuesday and Lewis will be with them, scheduled to get about nine innings — the Saints play a doubleheader with both games lasting seven innings — at DH on Monday. Should that go well, the plan is for him to play a full game at third base for the first time on Wednesday.

“We’ll re-evaluate where he is on Thursday, how he’s feeling, and we’ll make a decision on what we’re going to do through the weekend,” Paparesta said.

Does that mean he could come back on this road trip, or is he more likely to return after the Twins wrap up their weekend series in Boston?

“I would tell you this much — we’ve never done that with a guy,” Paparesta said of ruling Lewis out for Boston. “But when you miss as much time as Royce did, I think we need to be smart and give him as much time as possible to come back to make sure he’s ready.”

Briefly

Outfielder Austin Martin, who is on the Triple-A injured list with a mild hamstring strain, is in the middle of a running progression right now. … The Twins signed Matt Canterino to a two-year minor league deal, shortly after designated him for assignment. Canterino, who is rehabbing from shoulder surgery, is out for the entire season. The right-hander has been among the most intriguing arms in the Twins’ system for years but has dealt with a number of different injuries that have kept him off the field.