Everton face a row with the Nigeria FA over Joseph Yobo's availability.

Yobo was put on standby for Nigeria's Olympic squad.

Watford's Danny Shittu was also named as coach Samson Siasia said he would add three over-age players to the Under 23 squad for the Beijing Games, which are from August 8-24.

This means both players could miss the start of the domestic season on August 9.

FIFA regulations do not oblige clubs to release players for the Olympics but president Sepp Blatter has asked for co-operation.