Olympic and world 400m champion Jeremy Wariner says he is on course to break Michael Johnson's eight-year-old world record this season.
Wariner is keen to beat mentor Michael Johnson's world record
The American has a personal best of 43.62 seconds and ran 44.02sec last month in Osaka, on the track where he defends his world title in August.
Johnson set his record mark of 43.18sec in 1999 and Wariner said: "I'm right on schedule. It's in my sights this year.
"But I know if I force it, it will not come. I must run every race the same."
Johnson acts as Wariner's agent, and the 23-year-old admits his mentor's guidance has been crucial in developing his running.
"It's great to have him in my corner because he has been in the position I'm at and he is able to tell me some of the experiences he had, what I need to watch out for, how to stay on top and not give up," he said.
I'm out there doing the same thing that Michael did and what I've been doing the past few seasons
"He feels like I'd be able to break it but I know if I'm the one that breaks it, he'll be happy. But he knows it's going to take time."
And, with Johnson's former coach Clyde Hart also looking after him, Wariner feels he can only keep getting faster.
"Clyde is the biggest influence, he got me to where I'm at. I believe everything he tells me I need to do, I believe it will work.
"I'm not worried about other people's training regimes, I'm out there doing the same thing that Michael did and what I've been doing the past few seasons.
"It's worked already and it's not going to stop working."