ST. LOUIS -- Of all the things the stars of Major League Baseball had to have taken away from their meeting with President Barack Obama prior to the 80th All-Star Game on Tuesday, it's this:

The leader of the free world definitely does his homework when it comes to hardball.

On his way out to the mound to throw the first pitch to Albert Pujols in a packed Busch Stadium, No. 44 made sure to saunter through the clubhouses of the National and American Leagues to meet and greet some of his athletic heroes, sign autographs and talk a little baseball.

The players were impressed, to say the least, perhaps none more than White Sox starter Mark Buehrle, who plays for the former Illinois senator's favorite Chicago team.

As wowed as Buehrle was to be meeting a president, the fact that Obama wore a White Sox jacket out to the mound in a very much anti-White Sox city was even more dazzling.

"He told me he was going to wear a White Sox jacket, and I kind of thought he was [messing] with me," Buehrle said. "And he actually did it, so it was pretty cool.

"I was real surprised [when I saw it]. I looked up and I was like, 'Holy cow, he's actually doing it.' Everybody around me was giving me a hard time, saying, 'What the heck, he's wearing White Sox stuff.' That's how we roll in Chicago. We've got the president behind us."

Royals starter Zack Greinke wasn't exactly thrilled with that sentiment but said he understood.

"I should've told him the White Sox are terrible," Greinke said. "Instead I told him [White Sox outfielder] Jermaine Dye got robbed. He should've been on the All-Star team. He agreed."

Obama, while sitting in for an inning with FOX broadcasters Tim McCarver and Joe Buck, mentioned that fellow Hawaii native and Phillies outfielder Shane Victorino gave him macadamia nuts and a pair of spikes with the No. 44 on them. And then he talked about how relaxing it was to take in a ballgame.

"First of all, it's as close to home as I've been in a while, and this is the National Pastime," Obama said. "To go down there and meet Stan Musial and Bob Gibson and those guys, it's such a reminder about what's great in this country. You can't beat that, and it's a real treat."

But the real treat was for the players, even the ones who aren't American.

Mariners right fielder Ichiro Suzuki of Japan got an autographed ball from the president, who told fellow AL All-Star Curtis Granderson that he's a big Ichiro fan.

"My idea, when I saw him, was to say, 'What's up?' to him," Ichiro said through interpreter Ken Barron. "But I got nervous. You know, he has that kind of aura about him. So I got nervous and I didn't say that to him. I was a little disappointed about that.

"But I realized after seeing him today that presidents wear jeans, too. So my hope is that our skipper, [Don] Wakamatsu, was watching that and we can wear jeans on our flights as well."

Mets starter Johan Santana, from Venezuela, enjoyed meeting Obama, too.

"We shook hands," Santana said. "He seems to be a great guy. We had a great time, and the first thing he told me was, 'Oh, here goes a New Yorker.' That was kind of cool to hear that from him."

Obama's baseball knowledge seemed to blow everyone away.

"He was quite interesting," Yankees closer Mariano Rivera said. "He was wonderful. He knew about the cutter, which was great. He said, 'Keep throwing that cutter.' Outstanding. I always wanted to meet him and thank God I had the chance."

And when it came time to meet Boston's veteran knuckleballer, Tim Wakefield, Obama was prepared.

"He walked around and shook everybody's hands, and he got to me and I said, 'Mr. President, it's really nice to meet you.' He said, 'Oh yeah, you're the elder statesman here. I guess he had a joke with [Yankees shortstop Derek] Jeter earlier about being the oldest guy here and he said, 'No, I'm not. There's another guy that's older.'

"Afterwards, he was like, 'Hey, how do you hold that thing?' I showed him, like this. He said, 'You're going to have to teach me how to throw that thing one day.' I said, 'I will.' Then he was on his way."

Before he strutted out on the field, Obama even showed a little knowledge about a first-time All-Star, Oakland A's first-year closer Andrew Bailey.

"That was amazing," Bailey said. "He walked around the clubhouse and I said, 'Hi, Mr. President, I'm Andrew Bailey.' And he looked at me and said, 'Bailey ... you're the young guy. You're the youngest guy in here. The rookie.'

"I thought that was pretty cool."

And so did a man whom a lot of New Yorkers would probably elect president if they had the chance.

"It was real nice," Jeter said. "It was nice to get the opportunity to meet him. It was probably the thing I'll take most out of this All-Star Game. He just said that he was a fan.

"That's kind of hard to believe when you think about presidents, but that's pretty nice to hear."