KISSIMMEE, Fla. -- Seven-time Cy Young Award winner Roger Clemens, who's working as a special instructor at Spring Training this year for the Astros, put on a uniform and got back on the mound Wednesday for the first time in nearly six months, throwing live batting practice to Houston hitters for about 20 minutes.

Clemens, wearing his familiar No. 22 in the Astros' new color scheme, worked from both the windup and the stretch, and he even discarded the L-screen in front of the mound for his final few pitches. Carlos Pena, Rick Ankiel, Justin Maxwell, J.D. Martinez and Chris Carter were among the Astros taking their hacks against Clemens.

When he was done, a clearly tired Clemens was asked if he was getting ready to go back into the rotation.

"I'd rather have a glass of red wine than do that," Clemens said as he wiped sweat from his brow. "That was fun."

Clemens, 50, threw a mix of sliders and fastballs, and he called out the pitches to the hitters. He even barked a few batting tips as he was pitching.

"I got to face our big boys, and that was fun to see those guys and try and throw them some good batting practice," Clemens said. "Normally when I do that, it's for the hitters, and I want them to get their timing. I don't think I've been on the bump in eight months. That was fun."

The players said having Clemens on the mound raised the intensity of the situation.

"I faced him already at Yankee Stadium, faced him many times and in very tough situations," Pena said. "It's something that, as soon as he stepped on the mound, you transform immediately. That [feeling] like, 'It's Roger Clemens up there, let's go.' It's not just BP. You shouldn't ever take it lightly. If you don't focus when he's on the mound, there's something wrong with you."

Clemens said he was throwing at about 70-percent effort, joking he didn't want his elbow to come off with one of the pitches. It was the first time he had gotten on the mound in a uniform since throwing 4 2/3 scoreless innings for the independent Sugar Land Skeeters on Sept. 7.

"When you're in that setting there, you just want to throw strikes," Clemens said. "I'm probably a little shorter than most of the guys they're seeing. They're taking a lot of pitches for their timing. To see something in between their regular timing and coaches' BP is always good for them."

Clemens has been throwing to his sons back home, but he picked up the pace Wednesday to get through the batting-practice round.

"You get your mouth open and get winded, and [bullpen coach] Dennis [Martinez] was making me laugh standing behind me," Clemens said. "It was good for the guys. ... I'm real thankful I've taken great care of my body for the most part, and if my sister didn't make all those cookies and they didn't have Starbucks, I'd be really in game shape right now."

Wednesday marked the fourth consecutive day Clemens has been in Astros camp to work with the pitchers. He's scheduled to return in about a week, and again in the middle of March. Clemens has a personal services contract with the club.

"If I'm in the area and hear one or two of the hitters say, 'Hey, can you get up on the mound?'" Clemens said. "And if I feel good enough, I'll do it for them."

Outfielder Martinez soaked it all in.

"Roger's awesome," he said. "To be able to do that after not playing, he loves to go out there and play and pitch. It's almost like a game situation. He goes out there and throws and puts it where he wants it. It's not obviously as hard, but you still get to work on things you don't get to work on in BP."