MONACO (Reuters) - Usain Bolt says he is over his early season setbacks and running into form at the right time to sign off his career with two more gold medals at next month's world athletics championships in London.
Bolt labored to a 10.06 seconds 100 meters victory in the Czech Republic last month and immediately traveled to see his doctor German Hans-Wilhelm Mueller-Wohlfahrt for some treatment on the back issues that have troubled him for years.
The Jamaican world record holder will test his treated back in Friday's Diamond League meeting in Monaco, which will be his last outing before he defends his 100m title and then goes in the 4x100m relay in the world championships.
"I'm feeling good," Bolt told a Monaco news conference on Wednesday, before explaining how the death in a motorcycle accident in April of his close friend and former British high jumper Germaine Mason had hampered his progress.
"The season started off slow for me. I had a setback after my friend Germaine passed away, it kind of set me back a little bit," he said.
"I had some work to do so I've been a little behind schedule but I'm training well. I'm feeling much better over the last couple of days because I went to see my doctor in Germany and I've been training good, so that's a good sign, the weather's great here so hopefully on Friday it will be the same and I can perform at my best."
Bolt is unlikely to ever again match his best - the 2009 world record of 9.58 - and the 30-year-old said he would be happy with any sub-10 second time as he seeks to find the speed he knows he will need on Aug. 5.
"It's just all about execution now, going out there trying not worry too much about time," he said. "It would be good to dip under 10 seconds which will always help everyone's confidence."
Bolt, with eight Olympic and 11 world championship gold medals and a host of world records to his name, said the time was right to retire having achieved all his goals.
He laughed off the suggestion that he was running scared of Wayde van Niekerk and said he regretted that he was walking away just as the South African 400m and - as of last month - 300m world record holder was becoming the sport's newest star.
"I think that's one of the most disappointing things in my career now, that he came along at this late stage, that I didn't get to compete against him because I think he's one of the best hands down right now," he said.
"I'm never afraid, I love competition, but it's too late now, he's at the end of my career so, we'll never know."
(Writing by Mitch Phillips, Editing by Christian Radnedge)