Chelsea's loan policy has come under further scrutiny after Fifa confirmed it had received a complaint from Fiorentina over Mohamed Salah's switch to Roma.
The Premier League champions allowed Salah to join Fiorentina on loan in February and the Egypt winger impressed in Serie A.
Fiorentina have complained to world governing body Fifa after Salah joined domestic rivals Roma on a season-long loan this summer, alleging breach of contract. The claim is being investigated.
A Fifa spokesperson told Press Association Sport: "We can confirm having received a claim from the Italian club, ACF Fiorentina, against the English club, Chelsea FC, and the player, Mohamed Salah Ghaly, for breach of contract.
"The matter is still pending and being investigated."