Arsenal are counting the cost of Tuesday’s 1-1 draw away to Villarreal in the first leg of the Champions League quarter-final after William Gallas was effectively ruled out for the remainder of the season yesterday. Manuel Almunia and Gaël Clichy will also miss the second leg at the Emirates Stadium on Wednesday and the FA Cup semi-final against Chelsea tomorrow week as a result of injuries suffered in Spain.

Gallas damaged the medial ligament in his right knee in a collision with Giuseppe Rossi, the Villarreal forward, in the first half at El Madrigal. He will not have an operation, but Arsène Wenger, the manager, does not expect him to play before the end of the season given that Cesc Fàbregas, the captain, was absent for three months with a similar problem.

“If he comes back before the end of the season it is a good surprise,” Wenger said. “It is a grade two medial knee ligament injury. Fàbregas was also grade two, but he [Gallas] is a bit less [serious] than Fàbregas.”

Robin van Persie and Eduardo da Silva will have fitness tests before tomorrow’s match away to Wigan Athletic, but while Wenger’s squad is blessed with a number of attacking options, he does not have many defenders who are able to step in. “Not too many,” he admitted. “We have Mikaël Silvestre, we have Johan Djourou, but we lose Clichy as well for two to three weeks, so at the moment, of course, at the back we are a bit short.”

Lukasz Fabianski will continue in goal in place of Almunia, who sustained a foot injury against Villarreal, while Clichy, who injured his back, is expected to be replaced by Kieran Gibbs, the 19-year-old from London, who has yet to start a Barclays Premier League match.

“At the moment, yes [Gibbs will start],” Wenger said. “I will see how he plays on Saturday. I am confident he will do well. Fabianski as well, but personally I am not worried for them.”

Wenger played down suggestions that Gallas might have played his last game for the club. The France defender will have only one year remaining on his contract by the time he recovers, and, at 31, is at an age at which Arsenal seldom offer long-term deals. However, Gallas has proved his value to the squad despite being stripped of the captaincy in November for criticising his team-mates in an interview in France.

“Has he played his last game? That’s a big question,” Wenger said. “No, because he has one year on his contract to go. I envisage him being here next year. He had a challenging season. He has certainly had to cope with a major disappointment, but, on the other hand, we have to give him a lot of credit because he came back with great performances, so he dealt well with the situation.

“And he’s turned up in the big games with goals, when it matters, so that is very important. It was a good surprise.”