SportBacary Sagna and Kieran Gibbs doubtful for Wembley clashJames Olley13 April 2012Arsene Wenger has revealed Arsenal's defensive injury crisis has deepened after reserve full-back Kieran Gibbs picked up a groin injury in the Champions League victory over Villarreal.The youngster, standing in for injured left-back Gael Clichy, is a doubt for Saturday's FA Cup semi‑final against Chelsea at Wembley alongside right-back Bacary Sagna, who was unwell prior to last night's 3-0 win.Goalkeeper Manuel Almunia and defenders Johan Djourou, William Gallas are also unavailable, meaning Alex Song could partner Kolo Toure at centre-half with Mikael Silvestre switching to full-back, should Gibbs fail to recover.Wenger told arsenal.com: "We still have Sagna as a doubt from the weekend, and after last night we have Kieran Gibbs as a doubt too. He has a little groin problem."There is the option to play Sagna in there if he has recovered. The other is to play Silvestre in there and put Song at the back."There's not many other options but we'll deal with the situation no matter what happens."MORE ABOUTArsenalDavid Jones (Footballer)Mikael SilvestreWilliam Gallas