The only time Liam Ridgewell and Gary Cahill have been paired together for Aston Villa the night almost ended in disaster.

Villa found themselves 3-1 down at half-time in the Carling Cup to Wycombe Wanderers, their young centre-half partnership was found wanting in the air and David O'Leary's side were booed off at the interval.

To his credit, O'Leary did not bow to terrace advice that night. He kept faith with Cahill, and the Villa manager's faith was rewarded when his rejuvenated side stormed back after the break to win 8-3.

It also proved a watershed for Cahill, who had impressed in his six months out on loan at Burnley last season, winning the Clarets' player of the season.

After two more appearances back on the bench for Villa's next two league games after Wycombe, Cahill then suffered an ankle injury that has kept him out for three months.

And, insists O'Leary, it is only Villa's acute shortage of centre-halves that has put him in line for a recall against Portsmouth on Saturday.

Olof Mellberg is suspended, Martin Laursen is out for the season, and if Mark Delaney is ruled out, Cahill would get the nod. But O'Leary hopes the 20-year-old Yorkshireman will be all the better for that experience at Adams Park.

"I thought I'd take a look around and use that night to blood one or two young people and the two lads didn't need booing at half-time," said O'Leary. "They needed help and encouragement. They made mistakes and gave goals away but they weren't doing it on purpose.

"Gary had a good period on loan last season at Burnley. And, if you've any good prospects who have a chance, the way reserve football is now, you're best taking them out and giving them some-where where the football is better and stronger.

"Without a doubt, he'll be the better for the experience.

"But the Premiership is far, far different. And, if we have to play them both again on Saturday, they'll be learning their trade at the deep end.

"But you learn by your mistakes in this game and I'm looking for the supporters to get behind them."

Ridgewell went on to complete a run of 22 first-team appearances, brought about by Laursen's injury, before Delaney returned in early January. At 21, he stands by to be the senior central defensive partner this weekend and the Bexleyheath-born stopper insists that his lively London banter may prove a help.

"I love talking to people through the game," he said. "I do it all over the pitch, so I'll be able to coach Gary along if he's picked.

"But it's not all about me. Maybe he'll be able to talk and help me as well.

"We played together at Wycombe in the Carling Cup and it was strange thinking I was the older central defender. That was a fantastic night for the club to see two young centre-halves who have come through the ranks to play a senior game together. And it was good that it ended in a great win for us.

"Olof's loss speaks for itself.

Everyone looks to the skipper to lead the way and he'll be a big loss to the side. And Mark's a massive loss to the squad. Like me, he's a good vocal presence and he's been playing well recently, so it's a pity his knee has flared up.

"But Gary's come back from his injury now and I think he can go all the way. He's a big lad who likes getting stuck in and heading, so he has all the attributes to be a good centre-half."