When he's eligible -- and healthy enough -- to run, it's very hard to catch LaShawn Merritt. Those moments, however, have come around sporadically since the American won the 400-meter gold medal in Beijing. Merritt's latest problem, a tender left hamstring, caught up to him Saturday on the biggest stage -- the London Olympics. Looking to flip the script on a disheartening four-year period that included an embarrassing, 21-month drug suspension, Merritt pulled up halfway through his 400-meter heat and will not be around to defend his title. "It's very disappointing to ... be dealing with an issue and not be able to finish the race," Merritt said. "I'll regroup." By now, regrouping is routine for one of track's fastest runners. Read more: http://espn.go.com/olympics/summer/...rritt-pulls-qualifying-defend-400-meter-title
