TAMPA, Fla. -- As Joba Chamberlain emptied his last few pitches of the afternoon in the direction of home plate, the primary competition for the fifth-starter job stood off to the side, watching with a hand pinned to his hip.

Was Phil Hughes intently studying Chamberlain's form, looking for a hint of weakness to gain a point for one of the more compelling decisions the Yankees have this spring? Not quite. Hughes needed a running buddy, and he was willing to wait for Chamberlain.

So continued the amiable fight to round out New York's rotation, with both Chamberlain and Hughes pitching batting practice on a sunny Friday at George M. Steinbrenner Field. It's too early to begin handicapping, but the session served as a nice tease for what will be on tap next week.

"They've got to show us early," catcher Jorge Posada said. "They have to. Competition starts like that, and they have to show us from the get-go. I bet you there was a lot of eyes on today's BP, and as soon as they start throwing in games, you're going to see guys paying attention."

The "guys" Posada was talking about were, primarily, manager Joe Girardi and pitching coach Dave Eiland, both of whom watched part of batting practice from a perch behind home plate.

Chamberlain threw 33 pitches to Posada, Nick Swisher, Brett Gardner and Jamie Hoffmann, and Hughes fired 31 to a group that included Derek Jeter, Curtis Granderson, Robinson Cano and Jesus Montero.

Those names are formidable, but the assignments proved largely uneventful, because most of the pitches whizzed past the batters unchallenged, making it difficult to get a read on what could really be gained from Friday.

"Our guys are mostly going up there and standing there," Girardi said. "There's not a lot of them taking swings. ... That's the competitive nature that's inside of [Chamberlain and Hughes]. They're trying to throw well and open people's eyes."

Hughes said that he is trying to focus on commanding his fastball, and believes that his arm speed and velocity are fine for this time in the spring. He said that his breaking ball is bouncing a little more than wanted, though that's better than hanging it.

He is continuing to experiment with yet another changeup grip -- "I've probably had about 29 changeup grips in the last year and a half," he said -- which is more like a straight circle-change and could help him as a fourth pitch.

Chamberlain said that facing hitters helped him look at reactions a little bit, though pitchers are ahead at this point in the spring. Chamberlain said one of his goals is to improve throwing inside, tweaking his delivery and mechanics to become more consistent at that.

"Last year, I wasn't very good throwing inside," Chamberlain said. "Balls were coming back over the middle of the plate. That was something I wanted to work on, and I threw a lot of changeups, which was good. Right now, it feels better than it has in a long time -- or ever."

One of the highlights of the session was a pitch that got a little bit too inside to Posada, a darting slider that buzzed the catcher on his back leg. Posada jumped out of the way and stumbled a few steps toward the mound, raising his hands as he tried to regain his balance.

"It was good to get him out of the box," Chamberlain said, with a smile. "Get him a little uncomfortable."

That swagger will be one of the qualities the Yankees will be looking for during the Grapefruit League. Posada said that he likes how Chamberlain and Hughes have both handled themselves and grown since their debuts in 2007, and noted that spring numbers won't be the end-all to the debate.

"In Spring Training, you cannot look at stats," Posada said. "You have to look at it overall -- strikes, how hard he was throwing, how overpowering was he when he got in trouble. We want every one of them to get in trouble. How they step up and try to get out of it is very important."

Hughes said that he understands the stakes will be high, especially once those in positions of power begin charting the outcomes and appearances of every single pitch thrown off a Florida mound.

"I don't think you can have too many lapses with so much on the line," Hughes said. "It's not like you have three months of Spring Training. Once March rolls around and those games start coming, you have four or five outings. You need to start showing something.

"Out of those few outings you have, how many can you afford to not be on your game? I think it starts with [bullpen sessions], it rolls over into these BPs, and then you have to be ready when you get on a mound in a real game situation for the first time."

For now, all Chamberlain and Hughes can do is jockey with each other on paper, trying to ward off the challenger pack of Alfredo Aceves, Chad Gaudin and Sergio Mitre while getting into their regular routines -- and hope that it's enough.

"I knew it was going to be a competition," Chamberlain said. "Joe said that we're not competing [yet], but what I do today is going to dictate what I do tomorrow and in April and hopefully down the road. I knew it was going to be a battle."