Ex-Everton midfielder Tom Cleverley starred in Watford's 2-1 win over Arsenal.
Everton could do with a player of Cleverley's energy and dynamism in the centre of the park - shame Koeman sold him to Watford.
Watford beat Arsenal 2-1 at Vicarage Road on Saturday night.
Everton are reported to be getting rid of five unwanted players this summer, with Newcastle and Barcelona among their likely destinations.
The Senegal striker would also team up with another Everton flop, Tom Cleverley.
Many of the squad from five years ago have not gone on to have the careers they might have liked.
Everton midfielder Tom Cleverley will make his loan move to Watford permanent in the summer transfer window.
There were once high hopes that Jack Wilshere and Tom Cleverley might guide England to glory.
The former Manchester United midfielder looks set to join Watford permanently.
The midfielder is thriving after being handed the freedom to get forward at Watford - a luxury he wasn't afforded under Koeman at Everton.