Olympic marathon champion Eliud Kipchoge leaves for Berlin on Tuesday, with his sights trained on running his best ever race in the German capital on Sunday.
The 33-year-old, widely seen as the greatest marathon runner of the modern era, has won almost every major marathon on the calendar, but the world record has eluded him.
He was nevertheless cagey about his ambitions regarding the world record, currently held by compatriot Dennis Kimetto, of 2:02:57 - recorded in Berlin in September 2014.
"I am in good shape and feeling good. My training has gone on well. I just want to run my personal best, which stands at 2:03:05. If a world record also happens, that will be good enough," he told Reuters from his Eldoret training ground, 350km northwest of the Kenyan capital Nairobi on Tuesday.
"I am not thinking about the world record. My eyes are on a personal best," he said.
Kipchoge, who also won the world 5,000m title in Paris in 2003, clocked his best marathon time in the London Marathon in 2016.
His compatriot Sammy Kitwara, who will pace-run for him on Sunday, said the field had been planned for a world record attempt.
"Eliud will tackle the world record in a very tough field which includes (Wilson) Kipsang and (Zersenay) Tadese (of Eritrea). It will be a tough race. Eliud is going there to run for a world record," the 32-year-old said at his training base in the Ngong Hills just north of Nairobi.
"He would have broken it last year, when I also paced for him, but conditions were too hostile - it was too rainy and windy... We hope for the best this time. We have planned to pass the halfway mark at between 61:15 to 61:20. He is hoping to run a world record of 2:02:40 or thereabouts," he said.
Since debuting in the event in Hamburg in 2013, Kipchoge has won World Marathon Majors series runs in Chicago (2014), Berlin (2015 and 2017) and London (2015, 2016 and 2018).
He was second to compatriot Wilson Kipsang when the latter ran a then-world record time of 2:03:23 in September 2013, also in Berlin.