A host of stars will make their final London 2012 preparations at the London Grand Prix, which starts on Friday.
The two-day event boasts a strong line-up, including reigning Olympic 400m champion Christine Ohuruogu.
But Jamaican ex-world record holder Asafa Powell has pulled out of the 100m on Friday to rest his injured groin.
Powell's agent Paul Doyle insisted: "He'll be fine for the Olympics, but we decided not to race this week."
Gay dipped just under 10 seconds in Paris last week to pip Justin Gatlin, reversing the result at the recent US trials.
The final will be at 19:59 BST and will be followed by Farah running in the 5,000m in the final event to be shown during BBC Two's live coverage.
The 400m hurdles will feature Britain's strong Olympic trio, with world champion Greene back in action a week after setting a new personal best of 47.84 seconds in Paris.
Despite clocking that time, Team GB athletics captain Greene came second to Puerto Rico's Javier Culson, and the pair will face each other again, with Britain's Jack Green and Rhys Williams also involved.
"It has been a tough winter to get myself ready and it is all coming together at the right time," said Greene.
On his run in Paris, he added: "I thought the next time I got a PB it would be the British record, but on this occasion it wasn't quite. I skimmed 0.04 seconds off so there is only another two hundredths of a second to go. I would love to break the record, but I would love to get the gold medal more so.
"It is the biggest honour you can get as an athlete, to be part of the team and to be captain is fantastic. I was very proud when I got the phone call and I had to keep it quiet for quite a while, but it's a great honour."
China's Liu Xiang will look to use the Diamond League meeting to fine-tune his bid to win Olympic gold in the 110m hurdles, four years after missing out in Beijing. He takes on Britain's Olympic hopefuls Andy Turner, Andrew Pozzi and Lawrence Clarke, with Friday's final scheduled for 19:48 BST.
Hannah England has a chance to find form ahead of London 2012, the 1500m world silver medallist racing for the first time since damaging an Achilles tendon in May. England will race against fellow Team GB squad members Lisa Dobriskey and Laura Weightman.
The meeting also boasts a strong line-up in the field events, with Britain's new European champion Robbie Grabarz competing in the high jump and Greg Rutherford and Chris Tomlinson taking part in the long jump, both on Friday, while Olympic gold medal hopeful Phillips Idowu goes in the triple jump on Saturday.
The women's 100m on Saturday will see another intriguing clash when Carmelita Jeter, the second fastest athlete of all time at the distance, takes on Olympic champion Shelly-Ann Fraser-Pryce, the fastest woman in the world over 100m in 2012.
World champion Sally Pearson races against Danielle Carruthers, whom she beat to the 100m hurdles world title in Daegu last year.
Pearson set a best time in the world for 2012 at the Diamond League meeting in Paris, and the Australian is also set to face Britain's Tiffany Porter in Saturday's race.
"Last year was definitely a building year for me," said Pearson. "This time round I'm a tenth faster. Every year you want to get faster and hopefully I do. It's just a matter of keeping it simple and enjoying it.
"The Olympics come round every four years so you've got to thrive on it and just go for it."