Ahead of Monday nighta s FA Cup fixture against Manchester United, Arsene Wenger confirms that Gabriel is not available for selection.

Arsenala s latest signing, Gabriel, who started the game against Queens Park Rangers, suffered a little hamstring injury in the game. Gabriel is sure to miss out the FA Cup quarter-final against Manchester United on Monday night.

Wenger said: a Gabriel has a little hamstring injury and he will be out for two to three weeks. He has a scan today. That means hea s not available for the weekend and certainly not for West Ham United or Monaco, but after that he should be available again.a

Wenger confirmed that Szczesny will undergo a fitness test and if he clears it, he will play on Monday night. The manager also suggested that Nacho Monreal might come back. However, the manager suggested that more or less, it will be the same squad that started against Queens Park Rangers.

He said: a We will of course lose Gabriel in the squad and Nacho Monreal might come back. He will have a test today. Everybody else should be available – the same squad that played against Queens Park Rangers.a

a He has a test today. If he gets through that test, he will play on Monday night.a Wenger said about Szczesny.

It is expected that Szczesny will start the game between the sticks with Bellerin, Mertesacker, Koscielny and Gibbs as the back four.

Most of the other Arsenal players are fully fit and Wenger said that there is a lot of competition and it makes every decision difficult for Wenger, especially upfront.

He said: a We have a lot of competition going on in the team, especially up front – we have plenty of offensive potential. It makes every decision more difficult.a

Cazorla, Coquelin and Rosicky started in the midfield against Queens Park Rangers and the three are expected to feature against Manchester United as well. Upfront Ozil, Alexis Sanchez and Giroud are bound to start the game considering the trioa s form.

However, either of Theo Walcott or Alex Oxlaide-Chamberlain could start the game on Monday night. Meanwhile, Ramsey could also start the game ahead of Rosicky. Former Manchester United forward, Danny Welbeck is expected to make an appearance from the bench.

The game against Manchester United is very crucial for Arsenal as they look to retain the FA Cup. A victory, on Monday, will take them to the semi-finals of the FA Cup.