Molitor: Sano not very close to 100 percent

MINNEAPOLIS -- Miguel Sanó took batting practice and ground balls prior to Monday's 1-0 loss to the Mariners, but it may still be a bit before the Twins' slugger returns to game action.
Sano has been on the 10-day disabled list since May 1 (retroactive to April 28) with a left hamstring strain, and Twins manager Paul Molitor said that while Sano is making progress, he still isn't 100 percent healthy.
"I think he still is a little tentative, for me, and how he's going about it," Molitor said. "I don't know how you would judge the level of effort he's giving on some of the running he's doing, but to me, it's not very close to 100 percent. The swing's fine and he looks pretty good taking grounders and those type of things. But those hamstrings, like I've said -- to practice and try to get ready to where you can go compete in a game and then be able to sustain for nine innings, multiple days consecutively -- that's a challenge with that type of injury."
Molitor said the Twins hope to get Sano into a game "sooner than later" and that it helps that the team is in the midst of a strong stretch of play. But the ultimate deciding factor will be whether they believe he is fully healthy.
"Mostly, it's about doing the right thing for the right player at the right time," Molitor said.
Castro to undergo surgery
Twins catcher Jason Castro will have surgery to repair a meniscus in his right knee, Molitor said on Monday.
The 30-year-old backstop, who was Minnesota's starting catcher to begin the year, went on the 10-day DL on May 5.
Molitor said Castro will undergo a partial meniscectomy.
"He went out to Colorado. The opinion there is that surgery was recommended," Molitor said. "It's disappointing. Hopefully we'll get a little better feel on the length of rehab once the procedure is completed tomorrow morning."

Castro has been battling the knee injury for much of the season. Molitor said he has been told that the recovery length could be 4-6 weeks.
"It's one of those things where you know he has a history, and then he tweaks it," Molitor said. "Then he feels good. Eventually, it starts flaring up again, so you try to find out what's going on. Finally, between different people talking it over and analyzing his history and himself, and the images they were able to get through testing, this is probably the right thing to do."
Worth noting
• Ervin Santana threw to batters on Monday for the first time this season. It was a big step in his recovery from a Feb. 6 surgery in which a calcium deposit was removed from his right middle finger.
"He threw all of his pitches, had a good day," Molitor said. "He'll do that again on Thursday, with the idea of pitching an extended game next Monday."
• Twins right-hander Trevor May will head to Triple-A Rochester on Thursday to make a rehab start, Molitor confirmed. In his first start back since he underwent Tommy John surgery last spring, May threw three scoreless innings at Class A Advanced Fort Myers on Saturday.
"We've tweaked his schedule a couple of times as far as an extra start at extended before we start the rehab clock and those sorts of things," Molitor said. "But once we got him to Fort Myers, our goal was for him to have just one appearance there before moving him to higher competition."