Flamini told Milan Channel what to expect.
"Fabregas is a player with many qualities, as he has incredible vision and is also very good in front of goal.
"As for his defects, at times he 'forgets' to defend. Barcelona have great individual talents and play wonderful football, so they are among the favourites for the trophy.
"Admittedly, we would've preferred to face a different team at this stage, but they will certainly be two fantastic games.
"We will do everything possible to surprise Barcelona."