Frantic festive schedule leaves Arsenal manager Arsène Wenger with an injury crisis Thomas Vermaelen and Nacho Monreal are struggling with illness while Theo Walcott, Jack Wilshere and Tomas Rosicky all have injuries that could rule them out. Saturday's Cup tie will be their fifth game in 13 days and while Wenger usually makes significant changes for the FA Cup third round, he knows this is not possible for a north London derby. "It was not our first wish," Wenger said of the draw. I will have to go for it. You are not in a position where you can rest people. Wenger's need to avoid an embarrassing Cup elimination by Tottenham, means that his team to face Cardiff is set to be compromised. Wenger already knows that, for both Cardiff and Spurs, he will be without his two best midfielders this season in Ramsey and Özil. Ramsey injured a thigh muscle in the 3-1 Boxing Day win at West Ham United, and will be out for three weeks. Özil missed the 1-0 win at Newcastle United with a shoulder injury and saw a specialist on Tuesday. He is expected to miss two weeks. The recent build-up of fixtures has taken more victims, with Giroud struggling with an ankle injury. The French striker - who has started 26 of Arsenal's 29 competitive games this season - is keen to return for the derby but Wenger is more cautious. "Olivier is a strong structure and he recovers quite quickly," the manager said. He thinks he will be all right for Saturday, but the medical people think he will be a bit short. Kieran Gibbs also picked up a calf strain at St James' Park, while his understudy, Nacho Monreal, is struggling with the same illness affecting club captain Thomas Vermaelen. There are three other injury worries: Jack Wilshere, who has turned his left ankle, although not the one that ruled him out for a year; Theo Walcott, who has a shoulder problem; and Tomas Rosicky, who was kicked on the calf. Wilshere and Walcott did take part in training. "We had two intense periods plus we have played eight Champions League games since the start of the season," added Wenger. Our game was on Monday against Chelsea and all the other teams played Saturday. We played Monday [Chelsea], Thursday [West Ham], Sunday [Newcastle], and now Wednesday [Cardiff], Saturday [Tottenham]. So many games make some changes necessary. Newcastle was an intense game on the physical challenge. It is difficult to rotate without losing the balance of the team. If Walcott does not play, Arsenal will probably start with Lukas Podolski on the left and with Nicklas Bendtner up front. Wenger admitted that he is powerless to stop Bacary Sagna from signing a pre-contract agreement with a new club. The French right-back's present deal expires at the end of the season and he has shown little rush to agree a new one so far. Wenger said that the player and the club were "not far" from an agreement and promised that he would "push very hard to get it done." The reality, though, is that the longer it takes, the likelier it is that Sagna will leave in the summer, signing for Paris Saint-Germain or Monaco for a lucrative free transfer. He can do it, yes. We cannot stop him from doing that. Wenger insisted that Sagna's commitment would not waver over the final months of his deal. For me, that is not a problem because when you are a professional football player, you do until the last day, of where you are, your best.