Swansea City will have to make do without the services of Jonathan de Guzman for Saturday's Premier League opener against champions Manchester United at the Liberty Stadium.
The midfielder suffered concussion following a clash of heads with former Liverpool striker Dirk Kuyt during a training session with the Netherlands national side yesterday afternoon.
He was taken to hospital, where it was decided that he would need to recuperate for the next seven to 10 days.
As a result, he is also a doubt for next week's Europa League tie against Romanian side Petrolul Ploiest.
