Newcastle United midfielder Siem de Jong could reportedly face up to four months on the sidelines with a "serious groin tear".

The Dutchman, a £5m signing from Ajax, suffered the injury during a routine training workout, according to The Mirror.

The Magpies are yet to officially confirm the extent of the injury, with De Jong to undergo extensive scans once the swelling has subsided.

Losing the attacking midfielder would be a significant blow to Newcastle boss Alan Pardew, who missed out on signing Loic Remy from Queens Park Rangers during the summer transfer window.

De Jong has been plagued with injury since joining the Magpies, missing the opening-weekend clash with Manchester City with calf strain and bowing out of the Netherlands' international friendly against Italy on Thursday evening.