Emmanuel Petit
When: 2000
How much: £7m
Petit was one of the poster boys for Arsene Wenger’s transformation of Arsenal, having brought him in from Monaco he went on to be the perfect foil for Patrick Viera in what was a particularly tough midfield. Barcelona took a liking to him and sprang for his signature at the turn of the century.
However, it didn’t all work out at the Nou Camp as a series of niggling injuries limited his availability, and he would later concede that coach Llorenç Serra Ferrer didn’t know his best position as he frequently played him in the heart of the defence. Petit returned to England with Chelsea just a year later.