Grimaldi joined Sassuolo in 2004, from Serie B club Perugia, in a co-ownership deal.
[1][2][3] In the last season, which Sassuolo became the group stage champion of 2007–08 Serie C1, Grimaldi only played 12 times.
[4] At the start of 2008–09 Serie B, Grimaldi picked the no.23 shirt, but left the club on loan on 1 September 2008.
Grimaldi was an unused member of the Italy national under-16 football team during the team's 2001 UEFA European Under-16 Football Championship qualification campaign.
He was not called up to the U19 squad for the 2003 UEFA European Under-19 Football Championship qualification in 2002–03 season, however.