Nigerian forward Henry Onyekuru was forced off the pitch on a stretcher after appearing to damage his knee in RSC Anderlecht's 1-0 victory over KAS Eupen on Friday.
Onyekuru, who joined Premier League side Everton for £7.2m over the summer, was forced off the pitch with just 13 minutes left of the game, eventually being replaced Serbian left-back Ivan Obradovic.
Anderlecht won the game thanks to a goal from 18-year-old Francis Amuzu. However, Onyekuru's injury against his former side will be a major concern for Les Mauves et Blancs and Toffees fans alike.
Onyekuru was heavily linked with a number of clubs throughout the summer, with a move to Everton or Arsenal favoured due to the youngster's dream of Premier League football.
Eventually choosing to join Everton in the summer, Onyekuru was forced to return to Belgium on loan after having a work permit, something that is needed to play in England, denied.
The former KAS Eupen striker has scored nine Pro League goals since joining Anderlecht, with another coming in the Beker van België (Belgian Cup) against KVC Westerlo.
With Yannick Bolasie on the brink of making his first-team comeback for Everton, the Congolese winger will help bring so much needed pace and creativity to their starting lineup.
However, fans will be keeping one eye on Onyekuru's progress with the 20-year-old expected to be thrust into the Toffees' first-team next season.