Chelsea, Everton, Portsmouth, Sunderland and Newcastle United are facing the prospect of losing some of their African players for up to six weeks after Berti Vogts, the Nigeria coach, insisted that all members of his squad had to attend a 14-day training camp in January before the start of the African Cup of Nations in Ghana.

Barclays Premier League clubs are already concerned about the loss of players for the tournament, which starts on January 20 and ends on February 10, and they will be dismayed that Vogts wants players such as Obafemi Martins, of Newcastle, and John Obi Mikel, of Chelsea, to report for international duty on January 4.

"That is the way that things have to be and there will be no exceptions," Vogts said. "There will be a two-week training camp and all the players will be there. They will not be allowed to arrive later."

"I know some people say they were not injured but that is not true," Vogts said. "Maybe if the African Cup of Nations was played in the summer we would not have all these problems."