Marco Pantani returns to competitive action in the Settimana Coppi-Bartali race on Wednesday after a six-month ban.
Pantani won the Tour de France and Giro d'Italia in 1998
The Italian was suspended after being suspected of taking the prohibited substance insulin during last year's Tour of Italy.
The 33-year-old, who has always denied any wrongdoing, said he is determined to prove himself on the racing circuit.
"After a long time out there is always a fear that you won't be
able to compete at a high level," he told the Gazzetta dello Sport newspaper.
"But I have worked hard and my conscience is clear.
"Training has been very positive for me and I hope I can be up
there challenging with the best riders very soon."
World champion Mario Cipollini said he is delighted to see his compatriot and good friend back in the saddle.
"I, like everybody else who loves cycling, welcome Marco with
open arms," he said.
Pantani has not hit the heights since his double triumph in the Tour de France and the Giro d'Italia in 1998.
But he is a popular figure among cycling fans because of his flamboyant style and sense of humour.