It might happen, but it won't happen anytime soon.
The 30-year-old American had a memorable race in the German capital in 2009.
The world record holder has a knee injury.
Two of the top Kenyans square off Sept. 29 in the German capital.
Despite how close runners are to the magic mark, it doesn't seem possible right now.
The 29-year-old has not run a full marathon since the Olympic Trials last year.
Announcement comes on same day that three Kenyan marathoners get banned for doping.
He DNF'd there in 2012.
It's now the sixth event in the series.