Round of 16, First leg - 08/03/2012 - 21:05CET (20:05 local time) - Old Trafford - Manchester
Manchester United are set to welcome Chris Smalling back after his recovery from a head injury sustained during England's 3-2 defeat to the Netherlands last week and the former Fulham man may slot straight into the back line.
Anderson is also fighting for a starting place after two months out with a knee injury but the game comes too soon for Antonio Valencia and Tom Cleverley. However, the Ecuadorian winger may be in contention for the second leg.
Athletic boss Marcelo Bielsa will be without long-term absentees Aitor Ocio, Carlos Gurpegi and Xabi Castillo for the first-leg clash at Old Trafford.
Midfielder Ander Iturraspe missed the Bilbao club's Basque derby with Real Sociedad at the weekend but is expected to return to the squad in time for Thursday's clash, possibly on the bench.