FORT MYERS, FLA. - Twins catcher Joe Mauer, according to a club source, has been injected with Supartz, a solution that helps lubricate and create cushion in knee joints.

General Manager Bill Smith confirmed that Mauer received a shot after Tuesday's workout.

Mauer had his left knee scoped in December, and there was some hope he would be ready for the start of spring training. But Mauer has reported for camp needing some more time before he can take part in all phases of practice. And there's no telling when the Twins will start Mauer behind the plate in a spring training game.

Manager Ron Gardenhire on Tuesday indicated that Mauer might have received more than one shot -- although Smith confirmed only one had been administered.

"I'm just going to bide my time with that and make sure we get him in situations and get him ready," Gardenhire said. "It's more important for him to see the pitchers on the side, a few bullpens on the side, but I want to make sure we clean that knee up before we get anything going. He's had a couple of shots in it. It's not cortisone. It's some type of fluid to help lubricate."

Gardenhire was then asked if Mauer had the shots while in camp.

"Yes, I want to make sure those things take effect," Gardenhire said.

According to the company's website, the Supartz solution comes from "highly purified sodium hyaluronate (also known as hyaluronic acid [HA]) that is extracted from rooster combs. These are harvested from roosters that have been certified as suitable for human consumption via pre- and post-mortem veterinary inspection."

After approval, patients can receive up to five injections, although as few as three might work.

It's the same knee in which Mauer had meniscus removed in 2004, his rookie year,

Mauer, 27, had some problems with the knee during last season. When discussing the surgery in December, Smith indicated then that Mauer was dealing with a little irritation there.

In an e-mail response on Tuesday, Smith wrote: "Joe Mauer received a shot of medication to lubricate the knee joint. We will have him proceed slowly tomorrow, then work towards getting him back to full speed on Thursday."

Many athletes have had synthetic lubricants injected in their knees to help them through their careers. Twins pitcher Nick Blackburn had 90 percent of the cartilage in one of his knees removed after his 2002 season at rookie league Elizabethton and later had Synvisc injected into the knee, reviving his career.

Texas slugger Josh Hamilton had a Synvisc injection in September. And Synvisc is similar to Supartz.

Mauer has been seen all over the Lee County Sports Complex this week -- just not catching pitchers in the bullpen.

"He's feeling a lot better," Gardenhire said. "You can see him out there moving and feeling great, and we want to keep it that way. So we're going to kind of guard him and back him off and we'll eventually get him in the ballgames too."