The brother of AC Milan goalkeeper Gianluigi Donnarumma has joined the Serie A side on a four-year deal.
Antonio Donnarumma also plays as a goalkeeper and is nine years older than Gianluigi, who penned a lucrative new contract - complete with a £62m release clause - with Milan yesterday.
Antonio was previously part of the youth and senior setup at Milan but left in 2012 for Genoa, before more recently moving to Greek side Asteras Tripoli.
The confirmation of the deal means that Marco Storari is likely to become third-choice keeper at San Siro, with Antonio serving as understudy to his younger sibling.
Antonio is thought to have joined Vincenzo Montella's side for a fee of just £270,000.