Newcastle midfielder Siem de Jong could be out for "a number of months" with a thigh injury sustained in training.

The Magpies confirmed on their website on Friday that the 25-year-old Holland international has damaged his right thigh and faces a lengthy recovery period with a December return being predicted for the Dutchman.

A spokesman said: "Siem de Jong sustained an injury to his right thigh in training earlier this week and is to be assessed further at the start of next week.

"Initial indications are that he is likely to be out for a number of months."

The timing could hardly have been worse for manager Alan Pardew at the end of a week during which the transfer window closed without another striker being recruited, while at the same time Hatem Ben Arfa was allowed to join Hull on loan.

De Jong was seen as the man to link midfield with attack, playing behind loan frontman Emmanuel Riviere.

Newcastle have stuttered through the opening weeks of the new season, failing to score in either of their opening two Premier League games and being denied victory at the death in their third, a disappointing 3-3 home draw with Crystal Palace.

Pardew will now have to hope new recruits Ayoze Perez and Facundo Ferreyra, as well as midfielder Remy Cabella, can plug the gap.

De Jong missed much of last season at Ajax through injury and sat out a significant proportion of the Magpies' pre-season campaign with a foot problem.

His absence will do little to quell growing frustration among large sections of the club's support which reached new heights on the final day of the transfer window when the striker and defender they hoped might arrive failed to materialise and instead, Ben Arfa and central defender Mapou Yanga-Mbiwa departed on loan to Hull and Roma respectively.