On 4 March 2001, he made his debut for Milan, coming on as a substitute for Andres Guglielminpietro in the 78th minute of a home Serie A game against Parma.

During his stay with Napoli, he only appeared in four league matches and during the 2013–14 season, he was sent on loan to Verona, where he was a regular starter for the club.

Once his loan spell with Verona concluded, Donadel went on trial with Major League Soccer side Montreal Impact.

[15] Donadel was the captain of Italy under-21 team between 2004 and 2006 and won the 2004 European Under-21 Football Championship, totalling 31 appearances and 1 goal.

[19] Donadel returned to Montreal in December 2024, joining Laurent Courtois's staff at CF Montréal as an assistant coach.