But the Arsenal manager admits his captain has a mental barrier to get over before he can expect to recover his best form.
A year of hamstring problems are playing tricks on his mind, according to Wenger, and the Spanish playmaker did not possess his usual sublime rhythm when he came on as a substitute against Manchester United in the 1-0 defeat at Old Trafford a fortnight ago.
Is he pointing towards a successful second half of the season? Fabregas in training
There have been encouraging signs on the training field since but Wenger said: 'We have to move the hamstring out of his head. That comes from practising every day.
'It is hard to overcome if you have a recurrence of injuries because it plays a part in your head until you get rid of it completely, by reassurance. It is more a restriction when he comes on. The fact he has played 30 minutes has helped him but during that 30 minutes he was not completely himself.
'Physically I think he is ready. He has two more weeks of practice behind him and has looked sharp in the last two or three days. He has had the mental problem a little bit but it looks to have gone.'
It has been simple to pile blame on Arsenal's fragile mental state in recent years and such an attack usually prods Wenger on to the defensive with talk of age and potential.
Fabregas, the undisputed leader of his team, is only 23 and the players expected to line up against Chelsea at the Emirates will concede 44 years to those likely to be named by Carlo Ancelotti.
Wenger said: 'When you are 18 you are not completely the same man you are today. It is a process: how solid you are mentally at a certain age; how tough life makes you because it is not maybe so beautiful or nice to you as you think it is at 18.
'My players are quite solid mentally but they have not won yet and that is a mental hurdle everyone in life has to get over. One day you want to win and show you can win. For that you need to be tough and that makes you even stronger.
Not at his best: Fabregas came on as substitute during Arsenal's recent defeat at Manchester United
'I believe we have the right age to deliver and we want to deliver but the competition is very tough. We need a big win and Chelsea can be an opportunity. It would certainly speed up the maturing of this team.'
After the loss at Manchester United, Fabregas dared to venture that Arsenal were scared of their biggest rivals, stifled by the fear of losing.
'Scared is a big word,' said Wenger. 'But we played with a little bit of restriction at Old Trafford.
'It is down to the fact that the team wants to do so well. They are so keen to prove everybody wrong that it creates a little bit of a handbrake feeling in the team. But we will naturally get rid of that slowly. Do not forget that my players, at 20, were playing in the Champions League. They went to the semi-final of the Champions League, some of them went to the final.
'So they have mental strength. We had an opportunity to win the championship in recent years and OK, we didn't win it, but we are in a strong position now. Why should we worry whether we can do it or not?'
Chelsea's success in the last decade has been founded on the character and personality generated under Jose Mourinho and successfully harnessed again by Ancelotti.
They are a mature team in every sense and have a psychological hold over the Gunners. Of the 15 games between the teams since Mourinho arrived at Stamford Bridge in 2004, Arsenal have won two and lost nine, including the last five.
Didier Drogba has scored 13 in 11 games against the Gunners since joining Chelsea six-and-a-half years ago and has never been on the losing side against them.
If anything should encourage Wenger, it will be that the champions have also started to show mental cracks of their own, surrendering leads, dropping points and haemorrhaging confidence.
Drogba, weakened by malaria, has scored once from open play since the teams met in October and missed a penalty in added time against Tottenham on his last appearance, which would have won the game and stopped a rot which is now five Barclays Premier League games without a win.
Wenger said: 'Let's not focus too much on any weakness of Chelsea because that would not be right. They have experienced players, they always deliver good games against us so I don't expect them to come to the Emirates and lie down. They know as well it's an important game for us. It is a very important game for both. We only have one chance to win it and we must deliver a top-class performance.'
Wenger admits Marouane Chamakh's form has suffered due to a heavy workload. Chamakh, a free transfer from Bordeaux, made a strong start to his debut season but his influence has waned in recent weeks.
With Robin van Persie ready to start and Nicklas Bendtner also available, Wenger has options should he decide Chamakh, who has failed to hit the target in his last three matches, needs a break.
'Marouane has played nearly every game since the start of the season,' said Wenger.
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