Sir Alex Ferguson's men will learn the identity of United's opponents in the Champions League last 16 today when the draw is made in Switzerland (11:00 GMT), and the boss has no particular preference on who he'd like to play.
Bayern Munich, AC Milan, Porto, Internazionale, Lyon, Stuttgart and Olympiakos could all face United after finishing second in their respective groups.
Sir Alex has again been impressed with the standard in this season's Champions League and says every side left in the competiton could pose a threat.
"The standard has been very high this season – you can see that by how tight some of the groups have been. So it’s difficult to say who you’d want [in the last 16]," he told ManUtd.com.
"A few people maybe thought Stuttgart would be the weakest team, but they’ve got a new coach now [former Tottenham boss Christian Gross] and things change with new coaches.
"We’re pleased to have the second leg at Old Trafford and hopefully we can use that to our advantage."
Follow ManUtd.com's live blog on the draw from 10:00 GMT.