Channel 4 has dropped Ortis Deley as the main presenter of the World Athletics Championships in South Korea following hundreds of complaints.
A C4 spokesman confirmed it had "scaled back" his appearances, but that he would remain on air.
Deley, best known for presenting Channel Five's The Gadget Show, struggled with the live broadcasts.
It is the first time the championships have been shown on C4, after 27 years on the BBC.
Deley, who had limited experience of sports broadcasting, had difficulty with the pronunciation of athletes' and pundits' names and the demands of live television.
He will be replaced by Rick Edwards, who previously fronted the channel's world athletics highlights programmes.
Like Deley - formerly a presenter on CBBC - Edwards is best known as a presenter of C4's teen strand T4.
"Channel 4 is committed to developing new presenting talent and this extends to our coverage of sporting events," a spokeswoman said.
"Ortis Deley's role in Korea covering the world athletics has been scaled back but he will continue to be on air for the duration of the competition."
Olympic champion Michael Johnson and former British athletes Dean Macey, Katharine Merry and Iwan Thomas are among the 10 commentators fronting C4's coverage.
The channel will broadcast the Paralympics for the first time next year.