Gloucester trail their English rivals by just one point, having failed to secure a try bonus point against Mont de Marsan in Round 1.
But the Cherry & Whites have won both previous ties between the clubs in the Amlin Challenge Cup and notched up another victory in the English Premiership earlier this season.
Chris Hala'ufia is availabe after a successful appeal against a five-week suspension for an alleged dangerous tackle.
And Irish will welcome back England internationals Alex Corbisiero, David Paice and Jonathan Joseph and Exiles' director of rugby Brian Smith reckons their return will be a timely boost.
He said: "We have a lot of international players coming back. The challenge is to get them back into our system very quickly. We need to get them back into the groove."
• This is the first meeting between two English sides in the Amlin Challenge Cup since April 2011 and the quarter final clash between London Wasps and Harlequins.
• London Irish have lost only once in their last 13 home games in the Amlin Challenge Cup.
• Gloucester have won their two meetings against London Irish in this tournament, one of them in the Amlin Challenge Cup final in 2006 (36-34).
• Gloucester have won their last three away games in this competition.