SEATTLE -- Twins catcher Joe Mauer is taking another important step in his recovery from bilateral leg weakness, as he is scheduled to fly to Fort Myers, Fla., on Tuesday to begin workouts at the club's Spring Training complex.

There is still no timetable for when he'll play in his first rehab game, but he will continue to increase the intensity of his on-field workouts.

"He's got a lot more people down there to start doing field stuff," Twins trainer Dave Pruemer said. "He'll also get into some warmer weather. And he'll continue to do everything else he's been doing."

Mauer joins second baseman Tsuyoshi Nishioka (broken left fibula) and designated hitter Jim Thome (strained left oblique) in Florida, as they are also rehabbing at the Lee County Sports Complex.

Nishioka started sprinting drills on Monday and reported no discomfort, while Thome had four at-bats in a simulated game, according to Pruemer.

Thome is scheduled to play in his first full rehab game on Tuesday, and is tentatively scheduled to play in three extending Spring Training games before possibly joining the team this weekend when they play Arizona in Interleague Play.

Outfielder Jason Repko (strained right hamstring) is also scheduled to play with Triple-A Rochester on Tuesday to see better pitching, as he saw action in two extended Spring Training games.

Morneau serves as DH in opener vs. Mariners

SEATTLE -- First baseman Justin Morneau didn't fly with the team on Sunday night, as he stayed back to have his neck and left shoulder examined by team doctors.

But Morneau was cleared by the doctors, and arrived to Safeco Field about an hour before Monday's game and served as designated hitter, while batting cleanup.

"He stayed back last night just to double-check his neck and left shoulder that he's had trouble with," Twins trainer Dave Pruemer said. "And everything turned out [fine], and he can continue to keep playing like he's been playing."

Morneau has been dealing with neck problems all season, as he had a cortisone shot in his neck on April 22, and has also had similar issues in the past.

"He's had it off and on for a long time," Pruemer said. "He had it a little bit last year and the year before. And it bothers him off and on. So we just wanted to double-check on some things."

Twins manager Ron Gardenhire, however, said that Morneau served as the designated hitter only because of his late flight, and not because of his sore neck.

"With him getting in late and not being able to do everything you'd like to do to get ready for a game, it's just easier to DH him," Gardenhire said. "He can just get his swing ready, and not have to worry about throwing."

Swarzak, Dumatrait provide pitching depth

SEATTLE -- Twins' callups Anthony Swarzak and Phil Dumatrait saw their flights to Seattle get cancelled on Sunday night, and didn't arrive to Safeco Field until shortly before Monday's game.

But Twins manager Ron Gardenhire explained why he called up both pitchers, with Jose Mijares landing on the disabled list and Jim Hoey being optioned after Sunday's loss to the Blue Jays.

He said Dumatrait, who last pitched in the Majors in 2009 with the Pirates, had his contract purchased because of his success with Triple-A Rochester, as he posted a 1.15 ERA, despite walking 11 batters in 15 2/3 innings. Dumatrait also made his Twins debut on Monday, allowing one run in 1 1/3 innings in Minnesota's 5-2 loss.

"Dumatrait has been actually closing ballgames down there, so we know he can pitch late in games and spin the ball a little bit," Gardenhire said. "And we needed another lefty, with Mijares going down."

And Gardenhire said he liked the way Swarzak pitched in a spot start with the Twins coming on April 28, when he allowed five runs over 5 1/3 innings in the second game of a split double-header. He said Swarzak could see time in a long-relief role, but also hopes he can adapt to being a regular reliever.

"We just like the way he threw the ball when he came up," Gardenhire said. "He threw the ball pretty decent and has a good arm, and his mechanics are 100 percent better than last year. So we wanted to go with a different look, and go with a guy who's not afraid and won't back away. I'll just put him out there when I think we need him, and we'll see what happens. We'll probably have to give [him] a little more time to get loose because he was a starter."

Twins may see Killebrew in Arizona

SEATTLE -- With Minnesota heading to Arizona for Interleague Play against the D-backs this weekend, the Twins could potentially have a chance to visit with Hall of Famer and Twins legend Harmon Killebrew, who announced on Friday he was entering hospice care in Arizona, as his battle with esophageal cancer comes to an end.

But Twins manager Ron Gardenhire, who is close with Killebrew, said he'll only visit if it's OK with Killebrew and his family.

"I think you read in his statement that his plan was to share with his family," Gardenhire said. "That being said, we'd love to go see Harmon if we get that opportunity. But I also have total respect [for] him wanting to spend moments with his family, too. And totally understand that. So if there would be an opportunity, I would love to go say, 'Hi,' but I also have total respect for being around your family, and keeping it as calm as you can down there."