Eight-time Olympic gold medallist Usain Bolt hopes American sprinter Sha’Carri Richardson can “refocus” and get back on the track after she completes a one-month ban following a positive test for cannabis.

“Hopefully, she can learn from this and just push on,” Bolt said when asked about the American’s failed test for the banned substance, which cost her a spot on the US team for the Olympics in Tokyo.

“I know she has gone through a lot, but I hope she can refocus and just push on and do her best because she looks like a really talented athlete,” Bolt added.

Bolt, however, stressed that athletes needed to compete within the rules. “I’ve always explained to people that the rules are the rules.

“I’ve been saying this throughout my years, when it comes to drugs, I have nothing to say. But the rules are the rules. If they say you should do this and this is the rule, that is the rule,” said the Jamaican.

Cannabis is banned by the World Anti-Doping Agency (Wada), but if athletes can prove that ingestion is unrelated to performance, then a suspension of three months rather than the usual two or four years is imposed. If athletes are willing to undertake an approved treatment programme in collaboration with their national anti-doping body, the ban then can be reduced to one month.

Richardson was aiming to become the first American woman to win the Olympic 100m title since Gail Devers in 1996 after posting 10.72 seconds in April, one of her five runs under 11 seconds this season.

Coming back to Bolt, he took part in a promotional race here on Tuesday, trying for the first time in 800m. He clocked an unofficial time of 2:40 in what was a relaxed, fun atmosphere.

“In my mind, I thought 800m would be easier. It’s not,” Bolt said.