He might be the defending world champion but Dai Greene admits it will be a success just to make the final in Moscow with injury and illness leaving him running on empty.
It was just two years ago that the 27-year-old was on top of the world in the Far East, digging deep to claim global gold in the 400m hurdles in Daegu.
But fast forward to the present and all is not well with a knee injury affecting his Olympic preparations last summer and leaving him just short of the podium in fourth.
And this season has been another blighted by injury and illness with Greene suffering from a virus and both hernia and calf issues – the latter forcing him out of the Anniversary Games.
Lady Luck is clearly not on Greene’s side and if that wasn’t bad enough he picked up another illness on Friday that left him confined to his sickbed for the majority of Saturday.
Subsequently Greene came home fourth in his heat in Russia in 49.79seconds, good enough to see him into the semi-finals albeit nearly two seconds off his personal best.
And, while he lives to fight another day, Greene is adamant his wellbeing needs to change and quickly if he is going to have any hope of reaching another world final.
“It was very difficult and very tough out there,” he said. “Obviously I have had a tough last few weeks as I have not been able to do as much hurdling and that showed at the end.
“I was ill on Friday and Saturday as well so it’s been a nightmare last few days to be honest. I didn’t know whether I'd be good enough to run.
“I didn’t really know what I was capable of. Obviously we have the answer and it is not the answer we like but hopefully I’ll be a bit better for the semi-final.
“I’ve had this situation before where I’ve done one race and the next day I feel a lot better as a result of it, so fingers crossed I can rest up and put in a better performance.
“If I feel like this in the semi-finals realistically I have no chance of getting a medal. So hopefully I feel better and you never know what is going to happen in a race.
“So for me it was about getting to the start line and then try to get myself in the final in the first place.”
Greene will be joined by Rhys Williams and Sebastian Rodger in the semi-final, the latter squeezing through as one of the fastest losers on his World Championship debut.
In the women’s 400m hurdles event reigning European indoor flat 400m champion Perri Shakes-Drayton made serene progress through to the semi-finals.
The 24-year-old was drawn in between world champion Lashinda Demus and Olympic champion Natalya Antyukh in the heats but looked supreme in powering to the win in 54.42.
And the hurdler admitted afterwards that her self-belief has grown immeasurably after a superb season that has seen her lower her personal best to 53.67.
“That felt good, there was relief that I’m through though,” she said. “I knew it could happen but it’s just a relief that I’m through.
“It was good. I just need to rest and look after myself and recover properly and the semi-final is another day.”
Katarina Johnson-Thompson enjoyed a successful start to her senior World Championship debut as she sits fourth overall in the heptathlon on 2068 points.
The 20-year-old was just 0.01 off her 100m hurdles personal best as she came home in 13.49, before clearing 1.83m in the high jump.
However there was less good news for James Wilkinson and Brett Morse, who failed to progress in the 3000m steeplechase and discus respectively.
Morse could only manage a best distance of 59.23m in qualifying, more than seven metres down on his personal best, something he admitted would be gnawing at him for a long time.
“It’s very frustrating,” Morse said. “I've been in good shape all year and thrown very far and even in the warm-up I threw very close to the automatic qualification line and I was feeling good.
“Obviously technically things were off and in the World Championships it's unforgiving and I didn’t make the cut and it is as simple as that.
“It’s the first time I’ve walked away from a championship angry. I'm so much better than that.
“It doesn’t matter how far you can throw in Diamond Leagues or other meetings it is all about what you do in championships and I wasn’t good enough.”
© Sportsbeat 2013