World 200 metres champion Noah Lyles has said fellow American sprinter Christian Coleman must show more responsibility after he was provisionally suspended for breaching whereabouts rules.
Coleman, the 100m world champion, narrowly escaped a ban last year for missing three doping tests but was suspended in June after again breaching the rules.
He may now miss next year's Olympic Games in Tokyo.
Lyles, who along with Coleman was part of the United States relay team that won the 4x100m gold at the world championships in 2019, said a potential ban for his 24-year-old team mate could hurt their chances at the Tokyo Olympic Games.
"You are just hoping for a little more responsibility," Lyles told the BBC.
"It hurts because we want to go to Tokyo and aim for the world record."
Lyles, 23, had previously told US media that his relationship with Coleman was not good, but he said he did not want to see his compatriot banned.
Three failures to properly file whereabouts information or being absent at the hour stated, all within a 12-month period, can result in a one- or two-year suspension.
"You don't wish anyone to be missing tests.
"That's the quickest way to an accidental suspension. It hurts to see it in the track world," Lyles added.
"The whereabouts system has been pretty easy for me. I believe I've had two instances where I missed tests, one their fault, one mine.
"They happened in completely different years and ever since then I haven't had any missed tests.
"If you have missed one, definitely get someone to watch over that for you, to be that nagging voice in your ear," he said.
Just R20 for the first month. Support independent journalism by subscribing to our digital news package. 