Marco Ambrosio is a former Italian footballer who played as a goalkeeper. Ambrosio played for multiple teams in the Italian leagues from 1991 until his retirement in 2009, but also had brief spells in England with Chelsea, and in Switzerland with Grasshopper. He made two appearances for his country's under-21 side during the 1993-94 season, but never made an appearance for the full national side.
The early years of Ambrosio's career were relatively undistinguished, and saw him play for a succession of minor Italian clubs, such as Lumezzane, Atalanta B.C., Pisa, A.C. Prato and Ravenna. Whilst playing for Pisa, he made two appearances for Italy's under-21 team. He also had a stint with U.C. Sampdoria in Serie A. He made his Serie A debut on 2 November 1997, Sampdoria lost 0–3 at home to A.C. Milan. In total, he played 10 Serie A games for the Genoese team, as second goalkeeper behind Fabrizio Ferron. After Sampdoria were relegated to Serie B, Ambrosio was sold to Serie C1 team Lucchesein the summer of 1999, where he spent two seasons. In summer 2001 he was signed by newly promoted Serie A teamChievo, where he made another 10 Serie A appearances as second-choice goalkeeper behind Cristiano Lupatelli.
Chelsea
In June 2003 he was signed for Chelsea on a free transfer by Italian manager Claudio Ranieri. Ambrosio was signed to be goalkeeping understudy to Carlo Cudicini alongside fellow new-acquisition Jurgen Macho, and so found his playing opportunities limited at Stamford Bridge. Shortly after joining the club Macho picked up a serious knee injury and Chelsea subsequently signed Neil Sullivan, meaning Ambrosio would now compete with Sullivan while providing back up to Cudicini. His cause was not helped by an unlucky debut in the League Cup against Notts County, in which he made a series of errors. His second appearance, against Bolton Wanderers, proved far more assured as he made a string of impressive saves to secure a crucial 2–0 win for his side. That, together with injuries to all Chelsea's other goalkeepers, earned him a run in the side. His most significant contribution came in the Champions League quarter-final against Arsenal when his saves helped Chelsea to a 2–1 victory at Highbury. However, he lost his place in the side to the fit-again Cudicini towards the end of the season and with the signing of another new goalkeeper Petr Čech, he was allowed to leave the club on a free transfer in August 2004.