The Kenyan will have his chance to reclaim the title on the lightning-fast Berlin Marathon course this Sunday.
Kipsang is looking to become the first Kenyan to win in consecutive years since John Kagwe.
The stars are seeing the growth of running in their native countries, hoping it continues.
One exercise physiologist thinks its imminent and will happen sooner rather than later.
The pair will compete at the Mattoni Olomouc Half Marathon on June 21.