The IAAF 2015 World Championships will be one of the biggest sporting event in athletics this season. 

Athletes from all around the world will be participating in the 9-day mega event, which starts on 22nd August at the Beijing National Stadium, also known as the Bird's Nest, in Beijing, China.

The most-awaited event, the 100m dash, will witness some of the fastest runners of the world. Fans and experts around the world are eager to watch Justin Gatlin and Usain Bolt in the 100m sprint, which is expected to be a humdinger of a contest.

It was at the Bird's Nest where Bolt grabbed headlines all over the world with his incredible record-breaking performance in the 100 and the 200m dash.

A redux may not be possible, but Bolt is definitely one of the big favourites this time also. 

With Gatlin impressive during the year, Bolt, who has an impressive record against Galtin, will not find it easy. Some even claim Gatlin to be the favourite. Gatlin is also a 2008 Athens Olympics gold medallist, apart from being a bronze medal winner in the 2012 London Olympic Games 100m sprint.

Though Gatlin has been banned a few times, the American has been very sharp this year and could make the race against Bolt one of the highlights of his career, if he wins the prestigious 100m sprint.

Bolt has not been impressive for some time now as he has been plagued with injuries. He had to undergo a surgery on his left foot in 2014. Due to other injuries as well, Bolt's preparations have received a major jolt as he had to pull out of the Paris and Lausanne Diamond League. 

Bolt's coach Glen Mills feels that the champion athlete will perform at the world championship.

"The last two years have been very challenging for both Usain and myself," Mills told Reuters.

"Unfortunately, he has had a number of different injuries to overcome which have affected his training and the number of competitions he has been able to compete in.

"But Bolt is a champion who knows nothing but excellence when performing on the world stage," he said.

Mills may not have been able to train Bolt the way he wants to, ahead of the world championship, but Bolt the champion will give his best. 

"We have been making a number of changes on the way he trains and have been getting results," said Mills. "However, I would have wanted him to have had more races."