Arsene Wenger has every confidence Sol Campbell can produce the big game required against Wayne Rooney and Manchester United on Sunday.
Belgium defender Thomas Vermaelen, who has impressed since his £10million summer transfer from Ajax, is struggling to be fit to face the Premier League champions after picking up a knee injury in the midweek goalless draw at Villa Park.
Former Gunners captain Campbell came on as Vermaelen's replacement to make his first league appearance since rejoining the Gunners on a short-term deal.
Wenger has no doubt the former England centre-back can step in again should he be called for.
"Sol is ready, if he has recovered well. I have to assess him today, but normally he will play if Vermaelen doesn't play," said Wenger, whose side are now back in third place, two points behind leaders Chelsea following the midweek games.
"The good news we have on Vermaelen is that there is no fracture. "We have to assess his knee today, there is still a small chance that he plays on Sunday.
"We will do the maximum to get him fit, but at the moment it looks unlikely.
"It should be a very short-term injury, and at the latest he should be ready for the Chelsea game."
Campbell, 35, led the Gunners through their unbeaten league championship campaign of 2003/2004, when rivalry between Arsenal and United was at its height.
Wenger added: "Sol has experience and he likes the big games.
"He can turn up if needed and experience helps in these kind of games. Sol can cope with Rooney.
"I believe Sol has worked very hard and credit to him, every day he was motivated to push himself and he is quite fit, he looks fit."
Rooney is the Premier League's leading marksman with 19 goals, and was described by Campbell as United's "talisman".
Wenger, though, maintains Arsenal must concentrate on their own game. "I believe more than focusing on one individual performance on our side, it is important to focus on a good team performance," he said.
"We know if we play at our best we can beat Manchester United - we can beat everybody. "We want to do well in this league and that, of course, means at home you want to beat the big teams."
Wenger added: "Let's focus on our strengths and show that we have made a big improvement compared to last year.
"At Villa we were maybe a bit frustrated with the 0-0, but they have beaten Manchester United, Chelsea and Liverpool.
"We got four points from Villa, so I believe we have made big, big strides forward and that is a good opportunity on Sunday to show that."
