Bolton Wanderers boss Gary Megson believes David Moyes has more to achieve at Everton.
The Toffees travel to Bolton in the Barclays Premier League on Sunday, on the back of a series of disappointing results in recent weeks.
"I don't think it's for me to say how I see his future, but he hasn't reached a glass ceiling yet," said Megson.
"Everton is a huge football club. I had the honour of playing there 30 years ago, and it is a fantastic football club.
"David is a good friend of mine and he has done a terrific job at Everton. I think they are doing brilliantly and will continue to do so."