By Chris Harris

Arsène Wenger had a "bad surprise" on Monday morning - Alex Song has been ruled out of the Champions League trip to Barcelona.

The Cameroon midfielder was substituted with 19 minutes remaining against Wolves on Saturday with a groin problem but his manager expected him to be OK for the Quarter-Final second leg at the Nou Camp. But Song's injury is worse than first feared.

"It was a bad surprise this morning because he had a scan yesterday afternoon on his knee and he has an inflamed cartilage," said Wenger before leaving for Spain. "We have to wait and see how bad it is but he is completely out for the squad for tomorrow's game."

Sol Campbell was Arsenal's other doubt ahead of the second leg. The 35-year-old completed 90 minutes against Wolves but fatigue was always going to be a factor with two high-intensity games in just three days. Wenger will wait until matchday before deciding whether to pick Campbell.

"That is a decision I have to make after speaking to him tomorrow," said the manager. "Today he was still not completely available although he managed to get a warm-up. To go into such a game you must be completely fit or not play at all."

Arsenal squad to face Barcelona:

Manuel Almunia
Lukasz Fabianski
Nicklas Bendtner
Eduardo
Abou Diaby
Samir Nasri
Denilson
Fran Merida
Theo Walcott
Craig Eastmond
Tomas Rosicky
Armand Traore
Emmanuel Eboue
Gael Clichy
Bacary Sagna
Thomas Vermaelen
Sol Campbell
Mikael Silvestre

Copyright 2014 The Arsenal Football Club plc. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source 5 Apr 2010