The Brazilian has struggled all season with recurring muscular injuries and underwent a specialist consultation in Atlanta, Georgia.
"Pato is absolutely fine and I'd say we found the answers we were looking for," said chief Milan medic Jean Pierre Meersseman.
"We return home with a clearer idea of the situation. Could Pato play on Tuesday against Barcelona? Absolutely, he is ready and will certainly be at Coach Massimiliano Allegri's disposal."