Mary Cain, U.S. 1,500m champion, withdraws with a calf injury.
They could be held in Portland, Ore.
He defeated Mo Farah and a group of Kenyans.
Their coach thinks all runners can medal.
She's been dominating the indoor 300m since 2004.
He needs to check with his coach, first.
More records, world titles, medals and depth mark another noteworthy year.