By Chris Harris

Arsène Wenger may give Sol Campbell the chance to show that his Arsenal return was "worth it" on Wednesday night.

The 35-year-old could enter the heat of a Champions League battle in Porto after William Gallas was ruled out of the first leg with a calf injury.

Campbell has already featured in the FA Cup and Premier League since he re-signed for the Club last month and an appearance in Europe's premier club competition would be the defender's first since he scored for Arsenal in the 2006 Final against Barcelona.

A starting berth in Portugal would complete a massive turnaround for Campbell's career and Wenger has hinted that the former England international is in pole position to partner Thomas Vermaelen.

"It is a possibility that I don’t rule out at the moment because if he [Campbell] doesn’t play there it would mean you play with two left-footed players [Vermaelen and Mikael Silvestre] that I don’t really like.

"What it means to him is that he can show that his signing was worth doing and that he can help us to go through to the last eight."

Campbell for Gallas is not the only potential team change on Wednesday night after Alex Song, Andrey Arshavin and Manuel Almunia were also ruled out through injury. But Wenger trusts his Arsenal squad to get the job done in Porto even without some of the first team regulars.

"Ideally we wanted them there but I believe it is part of being in that competition that you focus on the players who play, not those who don’t play," said Wenger.

"The real question is 'can we make a good result with all the players who don’t go to Porto?', and I'm convinced yes. So let's focus on the players who play."

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 16 Feb 2010