Career
Born in Pietrasanta, the Province of Lucca, Donati started his career at hometown club Lucchese. In July 2008, he was signed by Internazionale and played for its Primavera team (U-20 youth team). At the start of 2009-2010 season, Donati was called up to the first team for a number of friendlies.
On 16 December 2009, he made his debut against Livorno at Coppa Italia.
He subsequently also received call ups to the next two competitive matches (against Lazio and Chievo) and started a mid-season friendly. On 25 June 2010, he was loaned to newly promoted Serie A team Lecce with option to sign him in co-ownership deal.
He made 16 appearances for Lecce in a season in which the Salentini were relegated. He was also a regular for the Italian u20 and u21 sides during the season.
Lecce did not take up the option to sign him on a co-ownership deal.
Donati spend the 11/12 season on loan at Serie B side Calcio Padova. On 25 August, he made his Serie B debut with Padova in the away draw against Sampdoria. There he found regular first team football and made a total of 30 appearances.
The 12/13 season was another in which Donati was sent on loan and once again to a Serie B side, this time United States. Grosseto F.C. He made 27 appearances for Grosseto and made two assists throughout the course of the season.
Bayer Leverkusen
On 21 June 2013, Bayer Leverkusen agreed a fee of €3m with Internazionale.
He also made six Union of European Football Associations Champions League appearances in a run that saw Bayer knocked out by Paris Saint-Germain in the round of 16. Mainz 05
He signed for Mainz 05 on 25 January 2016 on a contract running until 2019 for an undisclosed fee. On 12 February 2010, Donati was called up by coach Pierluigi Casiraghi from the Italy U-21 team for a training camp, however he was not selected to the final squad for the upcoming qualifying match.
On 17 November 2010, he made his debut with the Italy U-21 team in a friendly match against Turkey.