By Arsenal correspondent Tony Hughes

Arsene Wenger has defended his decision to play Petr Cech against Swansea even though he was not fully fit.

The goalkeeper has been ruled out for “three to four weeks” after sustaining a calf injury on Wednesday night in a shattering blow to Arsenal’s title hopes.

Speaking at his media briefing on Friday, Wenger admitted that Cech was carrying an injury going into the Swansea match, which Arsenal lost 2-1.

“Cech had a little groin problem but declared himself 100 per cent fit,” explained Wenger. “You trust the player. He is 33 years of age.”

However, Laurent Koscielny’s calf injury is not as serious and he should be back next week after missing the Swansea clash.

“Cech will be three or four weeks with a calf injury,” said Wenger. “Koscielny has a small injury and will be out for tomorrow.”

Both players will be absent for Saturday’s north London derby showdown at White Hart Lane as Arsenal attempt to get their title challenge back on track following consecutive Premier League defeats.

Cech, who has had an outstanding debut season at Emirates Stadium, will be replaced by his deputy David Ospina.

“I have complete confidence in Ospina, I don’t worry about that,” said Wenger.

Arsenal’s hopes of landing a first league title in 12 years suffered a heavy blow as Swansea came from behind to win at Emirates Stadium.

In other Arsenal injury news, Santi Cazorla has revealed that he hopes to be back playing within a month.