Wenger tight-lipped over keeper crisis

Arsenal manager won't be drawn on who will start in the north London derby

Arsene Wenger has admitted that he does not know whether to retain the increasingly erratic Vito Mannone, who has made a costly series of recent errors, or recall Manuel Almunia for tomorrow's north London derby as Lukasz Fabianski was yesterday discovered to have suffered a thigh injury against Liverpool. The Polish goalkeeper had impressed in the Carling Cup tie on Wednesday to make him the likeliest starter against Tottenham Hotspur but will now be out of action for three weeks.

"I don't want to give you an indication as I don't know who to play on Saturday yet," Wenger said.

It was Fabianski's first game of the season after recovering from knee surgery and his assured display had seemingly won Wenger's approval to plug a gap that has troubled Arsenal this season. "He has done very well," said Wenger, while the 24-year-old declared himself "delighted". The extent of the injury was not discovered until training yesterday morning. "It is a big disappointment," said Wenger.

That the Arsenal manager has maintained faith in the 24-year-old, whom he once described as having the potential to be "one of the greatest keepers in the world", illustrates the problems Wenger has had in adequately filling the position. Fabianski endured a disastrous FA Cup semi-final against Chelsea last year, proving culpable for both goals in Arsenal's defeat.

Almunia began the season a clear choice as No 1, but he has not played since conceding four times against Manchester City on 12 September. The Spaniard was initially sidelined with a virus, allowing Mannone, the No 3 back in August, his chance. The young Italian at first seized it with successive clean sheets, including enjoying an outstanding match in the 1-0 win at Fulham. Almunia has been back on the bench for the last three games to see Mannone take three steps back, culminating in palming a free-kick back into the six-yard box to allow Carlton Cole to spark West Ham's recovery on Sunday.

"Almunia is back to his normal level," said Wenger when asked about an apparent loss of faith in the 32-year-old, who only last season was being talked up as a possible England goalkeeper as he closed in on the qualification period. "I have no worries [about Almunia]."

Wojciech Szczesny is the fourth keeper to have played for Arsenal this season, appearing twice in the Carling Cup, but although highly thought of, the 19-year-old is regarded as a long-term prospect. Arsenal are far from alone in leaking goals more readily than in recent campaigns, but they have conceded 13 in nine Premier League games, more than Stoke and Birmingham.

Further forward, Wenger has fewer worries. Fran Merida was the pick of another young Arsenal side against Liverpool and the 19-year-old, who scored his first goal for the Gunners, has assured the club he is content at the Emirates. A move back to his homeland had been mooted – he came close to joining Levante on loan in the summer – given the lack of first-team opportunity for the Catalan who followed Cesc Fabregas's path from the Barcelona youth set-up.

"At the moment I am talking to the club so I don't know what is going to happen," said Merida, who is in the last year of his contract. "Hopefully, everything is going to be all right but we are going to sit down and talk about it. I am really happy here and things are going OK. I am really happy in London too so we will see what happens."