The Brazilian missed Saturday's 0-0 draw at AS Roma but aclub statement said he would travel to Manchester, where theSerie A side need to overturn a 3-2 first leg deficit.
Pato trained lightly on Sunday but was mostly confined to gym workbefore undergoing an MRI scan this morning which Milan's medical teamwill assess ahead of rhe clash at Old Trafford.
Return: Alexandre Pato
The striker is the key part of the three-pronged attack favoured byMilan coach Leonardo, who was forced to play strikers MarcoBorriello and Klaas Jan Huntelaar as a front two at Roma.
If the Brazilian is fit enough to start on the right of thetrio, Dutchman Huntelaar is likely to drop to the bench withRonaldinho and Borriello filling the other forward positions.
David Beckham would have been a candidate to replace Patobut the 34-year-old is now more likely to play on the right ofmidfield if Leonardo decides to bring the England man backagainst his former club.
Midfielder Mathieu Flamini played instead of substituteBeckham against Roma while Gennaro Gattuso is available at OldTrafford after a ban and Clarence Seedorf returns from a knock.
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