The 100-meter world record-holder makes his European debut this season at Thursday's Golden Gala.
The six-time Olympic champion has ran the 100 only once this year, narrowly edging one of his training partners, Kemar Bailey-Cole, in a photo finish in the Cayman Islands on May 8 in a relatively slow 10.09 seconds.
"I did have a bad performance but we went back to the drawing board and worked out everything. We figured out what went wrong. I'm confident now," Bolt said on Tuesday. "It's a long season. Last season started badly also, so I'm just going to keep working.
"My hamstring is much, much better now. There's no stress. I'm training hard and hopefully everything this season will continue to be good."
It's the third consecutive year Bolt is running at the Stadio Olimpico. He won in 9.91 in 2011 and in 9.76 last year.
Bolt's 100 world record of 9.58 was set at the 2009 world championships in Berlin.
"I'm feeling great. I've been doing lot of work on my speed endurance the last couple of weeks," Bolt said. "Everything is coming together. I'm happy where I'm at and my coach is happy where I'm at. I'm looking forward to going out there and doing my best."
The 100 field in Rome includes London Olympic bronze medallist Justin Gatlin and American teammate Michael Rodgers, both of whom have run under 10 seconds this year. Kim Collins, the 2003 world champion from St. Kitts and Nevis, is also running.
Gatlin should be Bolt's biggest challenger.
"I never worry about one athlete," Bolt said. "The big championship is always the big thing or me. He's done a lot this season already but for me it's when you show up and show that you're the best at the big championships and that's what I do, so I'm not really worried."
Preparing for the worlds in Moscow in August, Bolt will also run the 200 in Oslo next week before he returns home for the Jamaican championships. Then he'll come back to Europe for the 4x100 relay in Ostrava, Czech Republic, on June 27; the 200 in Paris on July 6; and the 100 and 4x100 relay in London on July 26-27.
Bolt's only significant loss in recent years came when he was disqualified for a false start at the 2011 worlds in Daegu, South Korea. Countryman Yohan Blake, who took the title that year, has been sidelined by a right hamstring injury but is slated to run at the Diamond League meeting in Lausanne, Switzerland, on July 4.
Blake took silver behind Bolt at last year's London Olympics and Bolt is looking forward to taking the title back at worlds.
"I strive on challenges," Bolt said. "Running against the best for me is always a joy, to show the world that I'm the best and I always want to be the best."
While he has swept the three sprinting golds at the last two Olympics, the 26-year-old Bolt still has things he would like to achieve — right on through the 2016 Games in Rio de Janeiro.
"I think I've accomplished all my dreams but I have a lot of goals," he said. "Now it's all about dominating the next four years. I'm looking forward to doing something that's never been done before at the next Olympics."
Meanwhile, he defended himself after being criticized for posting a photo on Twitter of a friend's clothing line that promotes "cannabis culture."
"They tried to make a big deal of it. I'm not going to really be stressed by that," Bolt said. "I know who I am and I know what I've represented over the years."
He also paid tribute to retired Manchester United manager Alex Ferguson. Known as a big United fan, Bolt has often said, half-jokingly, that he would like to try playing football when his track career ends.
"Me and Alex were friends so now that there's a new manager I'm worried it's going to be a little hard for me to make the team," he said.
This year's Golden Gala is dedicated to Pietro Mennea, the Italian who held the world record in the 200 metres for 17 years. Mennea, who won the 200 at the 1980 Moscow Olympics, died in March at 60.