Usain Bolt has said he is unsure how his pelvic injury will cope with the rigours of possibly running two 100m races at Friday's Anniversary Games.
The Olympic champion has raced once over the distance this year, clocking a pedestrian 10.12 seconds in April.
"I have worked hard in training so we will see how it is," said Bolt, 29.
Britons Mo Farah and Jessica Ennis-Hill are also among a number of star names competing at London's Olympic Stadium this Friday and Saturday.
Sunday will see several of London 2012's Paralympic stars take centre stage as The Stadium hosts the final leg of the IPC Grand Prix Series.
GB stars will include Jonnie Peacock, who is hoping to break a new world record in the T44 100m, David Weir, Shelly Woods and Richard Whitehead.
The 32-year-old Farah will race in Britain for the first time since doping allegations were made against his coach Alberto Salazar last month.
The double Olympic champion, who will line up in the men's 3,000m on the opening night of the two-day Diamond League meeting, has not been accused of any wrongdoing and on Thursday Bolt said he felt sorry for the double Olympic champion.
Both athletes will be under the spotlight when they return to the scene of some of their finest achievements.
There are those who question whether six-time Olympic champion Bolt can successfully defend his 100m and 200m world titles in Beijing in August, particularly given the form of rival Justin Gatlin, the fastest man over both distances this year.
"I'm very excited for Beijing and a little bit nervous," added the world record holder, who will run in the heats on Friday and then the final just over an hour later, should he qualify.
"I set the bar quite high last time [in Moscow]. I am not going there to lose. I always ensure I am ready for Championships.
"For me it just takes one run to get to 9.7. It is the first 40m that is important and if I get that right, I know I'll be ok."
The Jamaican said he wanted to "put on a show" for the fans on Friday, saying: "Everywhere I go there are always a lot of Jamaicans in the crowd, especially in London, and I come here for the fans. They support me and I want to do great for them."
With none of the top three athletes of the season - Gatlin, Asafa Powell and Trayvon Bromell - in London, Bolt's biggest threats are likely to be Frenchman Jimmy Vicaut, whose season's best 9.86secs is equal fourth fastest of the year, and compatriot Kemar Bailey-Cole and American Ryan Bailey.
British 100m champion CJ Ujah and fellow Britons James Dasaolu, Richard Kilty and James Ellington will also be taking part in the 100m.
(BBC)
