Officials told KickOffNigeria.com that Mikel and the Chelsea medical staff informed Samson Siasia that the midfielder would be unable to train or play on artificial turf as a result of his recent surgery. Mikel suffered medial ligament damage when he was caught by Robin van Persie in a nasty late challenge during Chelsea's defeat to Arsenal in December. The Nigerian has only just returned to first team football after undergoing surgery and spending over four weeks on the sidelines "They told the coach that if he plays on artificial turf now, it could cause a swelling in the knee where he had surgery," an official said. "But he is still expected to be in camp and meet up with the rest of the squad." That however, is not the case with Wigan's Moses, who is said to be developing cold feet "His advisers called to say that maybe this is not the right time for him yet, as it would be better for him to focus on establishing himself at club level." Officials remain hopeful that the youngster will join up with the rest of the team, although those expectations are derived more from optimism than certainty.