Sweden midfielder Kristoffer Olsson is suffering from multiple small blood clots on both sides of his brain as a result of an extremely rare inflammatory condition in his brain vessels, the player's club Midtjylland said on Thursday.

Olsson has been in hospital and put on a ventilator after the 28-year-old fell unconscious at home last month. He was admitted to Aarhus University Hospital where the club said he had undergone several scans and tests in recent weeks.