LONDON, England:

Despite handing out a failing grade for his athlete's second of two runs, coach Glen Mills was left generally satisfied with Usain Bolt's back-to-back 9.87 runs at the Sainsbury's Anniversary Games on Friday, inside the London Olympic Stadium.

Mills also confirmed that Bolt is unlikely to compete again before the start of the World Championships, ruling out suggestions he may show up at the upcoming Stockholm Diamond League.

Mills, after watching Bolt post his fastest times this season, believes the signs are encouraging as he focuses on sharpening up the sprinter ahead of his double-sprint title defence at the IAAF World Championships in Beijing, China, a mere four weeks away.

"To put it into context, he had one 100m before this in Brazil in April so between April and now is a significant period of time. So to start at 9.87 is an indication that he is making progress, and the focus is to continue getting his competitive condition to be at his best by the time we get to Beijing," Mills said.

"His performance is encouraging."

"It's clear that his (Bolt) performance in his heat was far superior to his run in the final, even though the times are the same," Mills assessed.

Mills believes the sprinter has gone a long way in showing that he is on the right course to dominate in Beijing.

"What I can say is that he (Bolt) showed that he has made some progress, and we hope that we can make significant advancement on that, so that, by the time Beijing comes around, he will be at the competitive level, where he can execute much better and defend his title," Mills said.