Mo Farah will face tough opposition in the IAAF/Cardiff University World Half Marathon after two notable entries into the field.
Double 2012 Olympic champion Farah will go head-to-head with Zersenay Tadese, the half marathon world record holder for the past six years.
Kenya's reigning world champion Geoffrey Kamworor will also defend his title in Cardiff on Saturday, 26 March.
Kamworor has said he is targeting a new world record time in Cardiff.
Farah, 32, is looking to win his eighth global title.
He beat Kamworor to the gold medal over 10,000 metres at the World Championships in Beijing last year.
Kamworor is the fourth fastest athlete of all-time over the half marathon distance.