Paris (AFP) - Karsten Warholm, the Olympic champion and world-record holder in the 400m hurdles, said Friday he was not 100 percent certain of competing at the world championships in Oregon that start on July 15.
Warholm pulled up injured on his return to competition at the Diamond League meet in Rabat in early June with a "muscle fibre tear" in a hamstring.
"It takes time to be able to recover from that," the 26-year-old Norwegian star told a press conference.
"It has been tough of course because it wasn't good timing at all.
"But I'm starting to feel better every day, I've been able to push it a little bit and haven't had any major setbacks so it's looking better and better.
"I'm starting to feel ready and starting to see some hope."
Warholm has been receiving treatment in Germany, combining work in the swimming pool with physiotherapy in his hope of being fit for Eugene.
"I've been doing everything in my power to be able to be ready, but in life you have no guarantees I guess," he said.
"I don't feel like I can say that I will run 100 percent yet.That's because I need to feel 100 percent.
"It's not the ideal situation but I've been working all the way since Tokyo to be able to be in a great shape.It's not like everything goes away because I've been injured for five weeks.
"The most important thing is that the hamstring can handle the pressure and I don't go out there and get an injury that's even more serious.
"I'm very eager to be on the starting line in Eugene to defend my title.
"I'm not going to go just to take part.I'm going to have goals if I go there.I'm not going to jog around.That's not my style I guess."
"It's going to be the biggest challenge of my career because I've never been in this situation before.
"Nobody knows what I'm capable of doing, not even myself, so it's going to be a mystery box this time."
After the worlds, where he would face fierce competition from the American Rai Benjamin and Brazilian Alison dos Santos, Warholm hopes to shine at the European championships in Munich from August 15-21.
