Last year was Oskar Kardin, Team Ragde Eiendom, ninth and best Swede at Vasaloppet and in the latest Visma Ski Classics race, Jizerska, he was second.

Now, however, Kardin may miss this year's Vasalopp due to concussion.

"I was out on a long training session and I crashed when I was almost at home in icy tracks", Kardin tells the Swedish media group Mittmedia.

"I have a headache almost all the time. It feels boring and tough," says Oskar.

The accident happened during a training session two weeks ago when he crashed and hit his head.

"I crashed on a downhill in an icy a curve. I stepped on but it was the ice that made the skis slide away and I landed on my head and got a blue eye,” says Kardin.

However, it wasn't until after he got home that he realized it was a more serious incident. After a medical visit, concussions were detected.

Kardin thinks that the chance that he can start at Vasaloppet on Sunday is pretty small.

"It's still unclear. Is it as it is today (Wednesday) I can not start. I'm waiting for it to get better, but right now there's maybe a 20 percent chance of me starting. Vasaloppet is something I've been training for a year and thought of almost every workout so it feels so boring.”