The 31-year-old full-back has returned to the Premier League from Atletico Madrid for an undisclosed fee.
Premier League: The England striker made his comeback after over four months out with a thigh injury in a 3-2 home defeat by Brighton on Sunday.
Premier League: Chelsea defender Ben Chilwell will undergo knee surgery that will rule him out for the rest of the season.
Toffees left-back Digne was sent off for a dangerous challenge on Kyle Walker-Peters in the second half, despite his claims he tripped when he stood on the Southampton defender's heel.
He was also one of the club's priorities in the transfer market after PSG were left with just Maxwell at the left-back position following the departures of Sylvain Armand and Saka Tiene.