Although Richardson's run was not an outstanding one, the possible absence of Johnson when the World Championships get under way in less than three weeks' time could turn out to be good news for him.
As the rest of the field left the stadium, Johnson remained at trackside to have his right leg heavily bandaged. Although he did not react with the instinctive jump that accompanies a traumatic hamstring injury, he was clearly tentative from the start of the race and slowed down gradually to a halt. Johnson has already missed his chance to run the 200m - for which he is world record holder - in Seville, having pulled out of the US trials as a precaution. This latest setback looks likely to ruin the rest of his season and at 31 the man from Dallas does not have years to waste.
For Colin Jackson, Britain's world 110m hurdles record holder, the World Championships cannot come soon enough. He demonstrated his readiness with a victory in 13.12sec, a stadium record, against a field which included the two fastest American runners this year.
In a 100m final won by Maurice Green in 9.87sec, Jason Gardener, the winner of last weekend's British trials, and Dwain Chambers were left struggling for the minor places. Gardener, who had bad starts in both his heat and the final, finished sixth in 10.10 while Chambers was last in 10.13. Green thus earned himself another $10,000 (pounds 6,000) one-carat diamond for a stadium record, having done so last season with a time of 9.90.
Jackson also earned himself a diamond, but it is gold which is on his mind. "Everything is going well for Seville," said Jackson, who has spent two weeks in Germany working on speeding up his trail leg, which he believes has been unbalancing him in recent races. "I've tried to concentrate on Colin Jackson," he said, "I am working on my strengths and forgetting my weaknesses. I tried to keep up the pressure on the other boys here from the start."
In the women's 800m, Kelly Holmes maintained her steady improvement on the run-up to Seville, where she is concentrating on the 1500m. Holmes, who has returned to top-class racing after two years struggling against injuries which threatened her career, has not yet regained the full racing shape of 1995 when she won world silver and bronze medals.
Although she was still in contention with the former world champion Maria Mutola at the start of the final straight, the Mozambique athlete pulled away to win in 1min 57.12sec. Holmes, however, kept her momentum to take third in 1:58.24, her fastest time of the season.
"I'm pleased about that," she said. "I'm getting better with each race and keeping everything on line for Seville."