Olympic champion LaShawn Merritt pulled up shortly before the home stretch in the men's 400 meters at the Herculis meet on Friday after feeling a twinge in his left hamstring.
The two-time Olympic gold medalist was challenging for the win in the Diamond League event before suddenly stopping after entering the final bend. The American runner then hopped up and down and held the back of his left leg.
''I went to cycle again and I felt it (the hamstring) kind of shake. It was like a cramp almost,'' Merritt said after the race, which was won by Belgium's Jonathan Borlee. ''It feels kind of tight, it feels like after a cramp. After you have a cramp you have that soreness, but the fact that I can do this (flexing his leg) is reassuring.''
The 26-year-old Merritt looked relaxed about the injury afterward, smiling and sounding optimistic about his participation at the London Olympics, which begin next week.
Asked if he thought he will be fully fit for London, Merritt said, ''Yeah, I think so,'' adding that ''we have a great medical staff at USA track and field'' as he continued to shake out and flex his left leg.
Merritt was confident of winning the race before deciding it wasn't worth the risk.
''So I was like `you know what? Let me stop this race.' I was about to move, I was feeling good,'' he said. ''This was a great field. I was curious how this would turn out, not with myself but the rest of the field. I'm feeling confident, I'll get this looked at, get ready for London.''