Didier Drogba is at the centre of claims that he isn’t eligible to play in the Champions League.
The former Chelsea striker made his return in the competition in Galatasaray’s 1-1 draw with Schalke last night.
It was the first time he has played in the tournament since helping the Blues to victory in the final against Bayern Munich last May.
But he is now facing claims that he should not have been allowed on the pitch to face the Germans.
Schalke are now considering whether to appeal but did not go into detail over their specific grievance.
A club statement read: ‘There are doubts about the validity of the permission to play for Drogba in the Champions League. Schalke 04 reserves its rights and is looking into this.’
Drogba signed for Galatasaray earlier this year from Chinese side Shanghai Shenhua – just six months after quitting Chelsea.
He is on an 18-month loan deal at the Turkish giants and is bidding to guide them to European glory along with Dutch ace Wesley Sneijder.
The controversy relates to the Ivorian’s former club in China, Shanghai Shenhua, challenging Drogba’s move to Galatasaray.
Shenhua officials previously claimed the Champions League winner remains under contract with them and it seems that Schalke are willing to test that argument with UEFA.
Shanghai Shenhua, who he joined from Chelsea last summer, issued a statement on their website earlier this month describing themselves as ‘deeply shocked’ by the announcement, and insisting Drogba remains under contract in China.
‘We understand that Drogba is eager to participate in the European Champions League,’ the statement read. ‘Shanghai Shenhua Football Club and Drogba on July 1, 2012 officially signed a formal contract for a period of two and a half years. The club has acted in accordance with this contract, and has effectively fulfilled the responsibilities and obligations of the club.