Physically Clemens and Pettitte tower over him by several inches and at least 20 pounds.
Roy Oswalt at first glance doesn't stack up next to his more celebrated teammates, but on the mound the 27-year-old right-hander doesn't have to take a back seat to any pitcher.
With 20 wins in each of the last two seasons and a career mark of 83-39, Oswalt has emerged as one of the best starting pitchers in baseball and a man Houston is counting on to get the Astros their first World Series victory when he takes the mound for Game 3 on Tuesday night here against Jon Garland and the Chicago White Sox.
"Roy's been our stopper," Astros third baseman Morgan Ensberg said. "He's come up big with us when we really needed him to. It seem like every time we need him to come through, Roy got it done."
Oswalt is unbeaten in postseason play with a 4-0 record and 3.10 ERA in seven career games, including six starts. He was never better than in the just-completed National League Championship Series, going 2-0 with a 1.29 ERA to win honors as the series MVP.
Oswalt capped that NLCS triumph with a masterful performance against St. Louis in the clinching game at Busch Stadium. The Astros, thought by some to be demoralized after coming within one strike of clinching in Game 5 only to lose on Albert Pujols' three-run homer, shut the door on the Cardinals 48 hours later, thanks to Oswalt.
"I think Roy in his last, well, all year long he's pitched well, his whole career he's pitched well in the big leagues," Astros manager Phil Garner said. "But the last few games he's shown a really tough determination and can-do attitude when he's been on the mound. And we certainly need him to step up and do that again. I really expect that he will do that."
Down 2-0 in the Series and coming off another walk-off-homer loss, the similarities heading into Oswalt's start in the World Series and his final start in the NLCS are obvious.
"It would be nice to get the first win, first game at home, so we can kind of switch momentum," Oswalt said Monday. "We played a good ballgame last night. We came up on the short end, but overall a pretty well played ballgame.
"The thing I like between both teams, they play the game hard, not really any showing up or anything -- it was a well played ballgame all around. We really need to win this, not to go 3-0 and kind of build momentum back to our side."
Getting run support early would be a significant factor. Oswalt is quiet, but he has a bulldog mentality and is awfully tough when he is staked to a lead.
"Offense still has to go out and swing the bat and get you in a situation where you can go right after the guys, instead of being so fine the whole game," he said. "Hopefully, if we get something started like Game 6 in St. Louis, where we had two runs early, it will give me the mind-set where I can go right after the guys, and play National League style ball. It will be to our advantage more than it is theirs."
Once given the lead at Busch Stadium, Oswalt picked apart the Cardinals lineup with an aggressive array of fastballs and two-seamers with an occasional breaking ball mixed in for good measure. His control, as it has been most of the year, was outstanding.
"The thing I noticed is in the first inning, I was able to spot my fastball where I wanted to," Oswalt said. "I was able to climb the ladder up in the strike zone whenever I wanted to and get guys to swing at some balls out of the strike zone up.
"I had good velocity that night and was able to sink the ball in and run the ball away from them, they couldn't really sit on just one pitch the whole night. I didn't throw a lot of breaking pitches, but had a real good two-seamer -- they didn't know if it was going to sink or run away with them."
Oswalt has been in a zone of his own in recent starts. As Clemens has battled a hamstring problem, Oswalt has quietly but clearly become the ace of the staff. He seems to have a quiet determination, not that it wasn't there before, but it's more noticeable now. His teammates say Oswalt is extremely focused.
"I think he's got his eye on the task at hand," Jeff Bagwell said. "He's going good and he knows what he has to do and has been doing it. He's the type of guy that can go out there against anybody and put up zeros."
Oswalt doesn't mind that the bulk of the attention goes to his teammates. In fact he prefers that it does. A quiet sort, he keeps his emotions in check.
"I've always been that way," Oswalt said. "I don't get excited a whole lot unless it's something really on the line. So I know tomorrow, once the game starts, where I'll be in the first inning."
That will be pumped up. This is, after all, the World Series.
"Well, you have to [get pumped up], once you get in the playoffs," Oswalt said. "The batters do. So you have to turn yourself up. During the season if you throw 250, 260 innings, every once in a while you don't have your best stuff.
"But once you get in the playoffs, it's a do-or-die situation. You have to turn it up a notch in the playoffs, because the other guys on the other side are battling a lot more. It comes down to a few games instead of 160 games."
For the Astros, it doesn't get any bigger than the first World Series home game in franchise history.
And they couldn't be in better hands.
Jim Molony is a writer for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.