Mo Farah says he will have his first "real" test of the season when he lines up against key World Championships rivals in the 5,000m at Sunday's Diamond League event in Birmingham.
Yenew Alamirew and Hagos Gebrhiwet, who have the fastest times over the distance this year, and world 10,000m champion Ibrahim Jeilan are competing.
"This is where it starts. It's the big one," said the double Olympic champion.
"It's a real, proper race. There's no-one missing in terms of the field."
The 30-year-old Briton, who produced a superb final lap to win the 5,000m European Team Championships title in Gateshead last week, said he was determined to keep his rivals at bay on Sunday.
"You're a world champion, Olympic champion, but you can't look at what you did last year or the year before. You're only as good as the last race, for sure," he continued.
British Olympic champion Greg Rutherford faces Aleksandr Menkov in the long jump, with the Russian leading the rankings this season.
Rutherford finished third in Gateshead and is struggling to find his best form because of a knee injury.
"I've got to find that groove again," he said.
"I've spent pretty much this entire year overseas training trying to get myself back into a decent shape.
"I've been giving it my all but when there a problem it makes it harder, but I'm just trying to get through that and hopes this knee issue goes and I can be as competitive as I was last year."
Britain's Olympic silver medallist Christine Ohuruogu faces Botswana's Amantle Montsho, who has run the three fastest times over 400m this year, while men's 400m hurdles world champion Dai Greene races against Olympic champion Felix Sanchez.
Olympic 100m gold medallist Shelly-Ann Fraser-Pryce of Jamaica is looking forward to renewing her sprint rivalry with world champion Carmelita Jeter of the United States over 200m.
"I've started the season well but I know there's more to come from me," said Fraser-Pryce.
"The 200m is looking very competitive already this year but I want to win and show that I'm still the woman to beat in the sprints going to Moscow [for the World Championships in August]."