Paging Jeremy Wariner. Your presence on the 4x400 relay team just became even more vital.

Wariner won gold in the 400 meters eight years ago and silver in Beijing, but didn't qualify for London after a less-than-stellar performance at U.S. Trials.

He made the team as part of the relay pool and just may be called upon to run the anchor leg of the relay.

Recently, that's been LaShawn Merritt's job. But the 2008 Olympic champion pulled up with a left hamstring injury in his qualifying heat Saturday and is out of the competition. His status for the relay is uncertain.

Don't write off Merritt just yet. He insisted he could be ready when the relay heats begin Thursday. The U.S. is trying to win the event at an eighth straight Olympics.

"We have some more time before the relay comes up," Merritt says. "If I go out and really hit it in practice and still feel it, I'll let somebody else run. We have a lot of depth in the 400, a lot of young guys."

Like Bryshon Nellum and Tony McQuay, who could also anchor the relay. Or even Wariner, who ran the last lap to bring home gold in 2008.

— Pat Graham — Twitter http://twitter.com/pgraham34

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