“The amount of goals they concede says to me that Martinez’s biggest weakness is the ability to defend,” Collymore has written. “His teams have a very good technical base and ability to keep the ball, yet things aren’t quite right at the back.
“Which is odd, because they have some very good defenders in Seamus Coleman, Stones, Baines, Galloway and Phil Jagielka. That’s the basis of keeping a lot of clean sheets.”
The former Liverpool striker has also given the Blues some advice for the January transfer window.
“Simple,” Collymore has written on Boylesports.com. “A central defender and a goalkeeper.”
Everton are 11th in the Premier League table at the moment with 27 points from 20 matches.
The Merseyside outfit are nine points behind Tottenham, who are currently fourth and occupy the final Champions League spot.
The Toffees will take on Manchester City in the first leg of the semi-finals of the League Cup at Goodison Park on Wednesday evening.
Everton will then face Dagenham & Redbridge at home in the third round of the FA Cup. The Merseyside outfit will lock horns with City again thereafter, this time away from home at the Etihad Stadium in the Premier League.