United States sprinter Tyson Gay has warned his rivals that he can run even faster as he prepares for Saturday's Diamond League meeting in New York.
Gay clocked 9.79 seconds in the 100m in a low-key meeting in Florida in his first race of the year last weekend.
"It was my first race and I was about 75%," Gay said as he prepared for his next event at Icahn Stadium.
World record holder Usain Bolt will not compete in New York but Gay will race against pacy Jamaican Steve Mullings.
Mullings, Gay's training partner, won the 100m in 9.80sec at the Diamond League event in Oregon last Saturday.
And Gay admitted: "He [Mullings] was running 10.00, now he's running 9.80, I have to step my game up to another level and see what happens."
The main goal this season for Gay, whose personal best time of 9.69 is second only to Bolt's world record of 9.58, will be the world championships in South Korea, starting in August, when the two are scheduled to go head-to-head.
But for now Gay is concentrating on maintaining fitness after recent battles with injuries, saying: "It's very frustrating - but at the same time, in some ways running with injuries or running hurt has made me the person I am today, made me fight harder."
Bolt blew his rivals off the track in his first 200m race in 13 months in Oslo on Thursday, the Jamaican running 19.86 - only five-hundredths of a second outside of Frankie Fredericks's track-record time.
Hepthathlon world champion Jessica Ennis will lead the British charge at the event, as she competes in the 100m hurdles.
Phillips Idowu,another victor in the 2009 World Championships in Berlin, is tied at the top of the Diamond League triple jump standings with Frenchman Teddy Tamgho and the pair meet once more.
Welshman Dai Greene will hope to overhaul in-form LJ van Zyl in the 400m hurdles after two defeats to the South African so far this season.
Saturday's meeting at Randall's Island near Manhattan also features two-time women's world high jump champion Blanka Vlasic of Croatia and three-time 200m world champion Allyson Felix of the United States.
Vlasic, the 2010 world athlete of the year, is building form and fitness after an illness in January which resulted in her missing.
She has a personal best (PB) of 2.08 metres only one centimetre below the world record set by Stefka Kostadinova of Bulgaria at the 1987 world championships in Rome.
"I can't not think about [the world record], because somebody always asks me about it," Vlasic said. "I'm trying not to be under too much stress. It's something that I would like to do.
"I'd like to go one step forward to break my PB, and my new PB would be also the world record."
For South Africa's Oscar Pistorius the meeting offers him another chance to qualify for the 400m at the world championships.
The double amputee, who has fought a long legal battle to compete against able-bodied athletes, has a best time of 45.61 and needs to get down to 45.25 to qualify.
"Every race, we pretend is the race I need to qualify," said Pistorius.