Cesc Fábregas has told Arsène Wenger that he is fit and ready to play for Arsenal against his former club, Barcelona, in the second leg of their Champions League knock-out tie on Tuesday, though his availability is likely to be offset by the absence of Alex Song from the visitors' midfield.

Song sustained a knee injury in the Carling Cup final defeat by Birmingham City and has not trained since, with a final decision to be taken on whether he is to travel to Catalonia on Monday.

"At the moment it does not look like Alex will be fit," said Wenger. "He's not been on the field at all since Wembley." The squad are due to train at London Colney on Monday morning before flying to Barcelona, with the Arsenal manager conceding he will need "fresh legs" at Camp Nou following the goalless draw against Sunderland yesterday.

Fábregas, who suffered a hamstring injury early in the victory over Stoke City 11 days ago, will undergo a definitive fitness test on Monday but is confident he will be able to feature and is relishing his return home. The Spaniard was denied the opportunity to play at his former club last season having suffered a broken leg in the 2-2 draw at the Emirates Stadium in the first leg of their quarter-final but Arsenal share their captain's optimism that he can start on Tuesday as they seek to defend a 2-1 lead from the exhilarating first game last month.

Jack Wilshere, who hobbled away from the draw with the Wearsiders, has also declared himself fit and says the Premier League side will travel to Spain confident they can progress in the Champions League at Barcelona's expense. "We now know we can beat them, as we did at the Emirates," said Wilshere. "We showed in the first game that we have the character to come back from a goal down against the best team in the world and we are going there with a massive amount of confidence. Hopefully we will get what we need.

"We know we will have to defend well and hit them on the counter-attack but, if we get a goal, they will have to come at us. It will be massive to have Cesc back – he is our captain, our leader, and probably our best player. We know we can win there. Beat them and we'll have a good chance of winning the tournament."

That sentiment is shared by Bacary Sagna, who was suspended from the first leg but will play at Camp Nou. "Barcelona created many opportunities and we were a little bit lucky that they only scored one goal," he said. "But I ended up reassured. Despite this goal, we did not give up and we won. We saw that they were not invincible. They have some weaknesses so we must try to put them under pressure."

Wenger suggested he may start the second leg with Marouane Chamakh, who played 28 minutes on Saturday, as his lone forward in preference to Nicklas Bendtner in that role and in the absence of the injured Robin van Persie.

"Marouane's getting back to his best, and getting sharper," the manager said. "We'll make some changes for Tuesday, that's for sure. We need some fresh legs for the Nou Camp because we'll have to run a lot there.

"We've not got enough security just to sit back and defend; you can't go to Barcelona and play for a 0-0. Anyway, it's not the personality of my team. This game has been hanging a bit over the heads of my players but our focus is on it now."