Wilkins revealed that Cole's removal was a tactical decision by Carlo Ancelotti with Coca-Cola Championship side Cardiff holding the Blues 1-1 at the interval.

Chelsea had gone in front in the second minute through Didier Drogba's 23rd goal of the season but Michael Chopra put City level before the break.

Second-half goals from Michael Ballack, Daniel Sturridge and substitute Salomon Kalou ensured holders Chelsea reached the quarter-finals.

Cole, who has yet to sign a new contract with the Blues, is struggling to prove to England manager Fabio Capello that he can play a part at the World Cup finals this summer.

The midfielder was sidelined for much of last year with knee ligament damage but Wilkins insists there is no problem with Cole.

"Joe wasn't injured, it was just a tactical thing," said Wilkins.

"We have a squad full of quality and therefore the manager will change things if he sees fit.

"We are very fortunate as far as that is concerned. I am not concerned about his form.

"When you have had a long lay-off like Joe, it really is a shock to the system. But it does take a bit of time to get back into your tip-top form.

"That will come with Joe. He is working extremely hard day-by-day, so we don't see any problems there at all."

However, Wilkins did admit Cardiff posed them plenty of problems in the opening half.

Thankfully for the holders, their experienced players, like Ballack and Drogba, came to the fore.

"It was tougher than we thought," added Wilkins.

"We anticipated having a hard game. Cardiff played exceptionally well and gave us a lot of problems in the first half.

"But thankfully we managed to up the tempo in the second half and it became a tad easier for us. But we have got to give Cardiff credit as well. For an hour they gave us a tough old game.

"Our team was changed but we took quality out and quality came back in. It is the professionalism of our players that shines through.

"Some people might have thought this was going to be a bit of an easy game for us but those guys took it by the throat and pulled us through when we were not playing particularly well.

"I would include Frank Lampard in that as well. Full credit to those guys."

Defeated Cardiff boss David Jones paid tribute to his players after they threatened to pull off a major cup upset.

"It is hard on them because the scoreline looks like it has been a bit of a drubbing," said Jones.

"That bit of quality has come through for them. Certainly for over an hour we gave a good account of ourselves and showed great character after going a goal down after a couple of minutes.

"I decided to come here and have a go. Every player today deserved a lot of plaudits because they worked their socks off but you get undone by the little bit of quality their guys have.

"We regrouped after conceding an early goal and stuck to our gameplan when they were in possession.

"We grew in confidence and their keeper pulled off some fantastic saves. But as the game went on they imposed their quality.

"It gives us some credit that Ancelotti brought on his big guns. Great credit to our lads though.

"Chelsea is the best club in their division at the moment but when you look at the players they have got, it was a great achievement from our players.

"I cannot fault them in anything they have done, they were magnificent. It looks like a drubbing but it was far from that. This result is done and dusted now it is back to the bread and butter on Tuesday.

"I've come here with players that wanted to play. You don't come to places like this and play as well as you have and be downhearted, we go again.

"Even when they lose, they have never let me down. I've now got to get them up again for a big one against West Brom but we have great camaraderie."