Born in Pisa, Signorini started his career playing for his home team, Pisa S.C. of Serie C1, and successively for Pietrasanta, Prato, Livorno, Ternana and Cavese before joining A.C. Parma, with Arrigo Sacchi as coach. He quickly became a key player for Parma, helping the club to Serie B promotion in 1986, winning the Serie C1 title.&lt;ref name="1985/86"&gt;&lt;/ref&gt; He was successively signed by Nils Liedholm's A.S. Roma, and then to Genoa in 1988, after personal requests by coach Francesco Scoglio; during his first season with the club, he immediately helped the team to Serie A promotion by winning the 1988–89 Serie B title. In total, he played seven seasons for Genoa, all seven years as team captain; a hard defender and a fan favourite, he is remembered as one of the last (and best) Italian sweepers. In his later years at the club, he was a vital member of the Genoese "dream team" which managed to reach the semi-finals of the 1991–92 UEFA Cup, and became the first Italian team to beat Liverpool F.C. on their Anfield Road home turf; he also helped the team to a fourth-place finish during the 1990–91 Serie A season, the club's best league finish since the end of the Second World War.