Cameroon's Samuel Eto'o feels his knee is too weak to play

The striker's absence is reportedly unconnected with his criticism of coach Frank Rijkaard on Tuesday.

Rijkaard said: "Eto'o has told me he feels his fitness is improving but that he would prefer to stay in Barcelona to continue working to achieve his peak form."

Eto'o was said to have been angered by claims that the striker refused to play

as a substitute in Barca's win over Racing Santander.

It has been reported Eto'o asked to be omitted from Sunday's squad because his right knee is still weak.

The striker was sidelined for four months after picking up a knee injury during a Champions League match at Werder Bremen.

The 26-year-old made his return towards the end of Barcelona's 0-0 draw with Osasuna on 4 February.

Eto'o has been replaced in the 18-man squad for the game at Valencia's Mestalla stadium by Iceland's Eidur Gudjohnsen.

The match comes three days before Barcelona continue their Champions League title defence against Liverpool.