Diafra Sakho reported back for training at West Ham on Friday morning, according to Sky sources.
The forward is likely to be fined for missing training on Wednesday and Thursday as he tried to force the club to sell him to Rennes.
He flew to Rennes on Wednesday in his agent's private jet to have a medical without West Ham's permission.
Sakho believed West Ham had agreed to sell him to Rennes in a £9m deal.
He returned from France yesterday for talks with West Ham but first went to Chelmsford racecourse, where he made £550 from backing his agent's horse Siege of Boston.