MARTIN O'NEILL thinks he can help Sunderland captain Lee Cattermole curb his bad-boy image, but admits 'I don't want to change him too much'.

Stockton-born Cattermole is the most excited member of the Black Cats camp this weekend as he prepares to go head-to-head with the club he supported as a boy in tomorrow's FA Cup fourth round tie.

It will be the third time the 23-year-old has faced Middlesbrough, but the first time he has captained North-East rivals Sunderland against them.

And there are fears he will add to the eight yellow cards he has picked up this season against Boro, knowing he is couple more bookings away from a two-match ban.

But there can be no disguising the high level of his performances for Sunderland since O'Neill took over at the beginning of December - even if there have been off-the-field problems along the way.

And having been impressed by most of Cattermole's attitude and personality, O'Neill hopes to help the Teessider cool it on the pitch as well as off it.

"Do we think we've helped him in his discipline? I wouldn't be convinced about that yet at this minute," said O'Neill. "He's picked up eight bookings this season and is two away from a ban. The months ahead will be too long (to avoid) that.

"I don't accept that it's his game. I think you can help, there are times his challenges have given us all a lift, and other times when he can definitely avoid it.

"I wouldn't want to prevent that wholeheartedness and courage, which is terrific, great. Considering I wasn't the best tackler in the world myself, I appreciate what he does but there are just sometimes when he could be a bit more careful. I'm hoping that will be something he can learn."

Cattermole has spoken a number of times in the last few weeks about the decision O'Neill made to stand by him as captain despite a couple of early disciplinary problems he encountered. One, most notably, was after a night out with Nicklas Bendtner in Newcastle, while there was another too.

"Early on, he had a bit of a problem, he missed training because he was in Scotland, my first week there," said O'Neill. "He was unable to get back and so he incurred a fine. So he really got off to a good start!

"Then he had another on-going problem so I thought this was really great. I know Scotland's north of the border, it's possible despite the high winds to get back. You may have to take a boat and go around Plymouth, but you can get back to this country. Since those early hiccups..."

Given Cattermole's strong relationship with former manager Steve Bruce, it would have been easy for O'Neill to have made the midfielder the scapegoat for much of what had gone on before.

Instead, however, the Northern Irishman has revealed he quickly realised, more than he thought, about the benefits of having a player like Cattermole leading the team.

"You get some sort of perception about players but I'm pretty willing to change those, particularly if you start get to know someone," he said. "I've been pleasantly surprised with him.

"I'm saying these things now and in three or four weeks time I'll probably be changing my mind. He's been a fantastic influence and considering he's only 23 he's got real genuine leadership qualities.

"What he says in the dressing room he attempts to carry out during the game. I couldn't ask for much more for him.

"Lee and Steve got on very well indeed, there was a strong rapport and I'm never one to come into a club and to really worry about the players felt about the other managers.

"There would have been one or two players who would have been very sad to see Steve go and that's great credit to him. That part has gone and you try to develop some rapport with the players, sometimes that doesn't occur."