Geneva - Slovenian Simon Spilak faces a tough challenge to keep his yellow jersey for Tour de Romandie, which starts Tuesday, with Australian Cadel Evans, Italian Ivan Basso and Russian Denis Menchov among contenders.
Evans missed this month's Ardennes Classics campaign due to a knee injury, while Tour de Italy champion Basso had pulled out of the Tour of the Basque Country due to illness.
Nevertheless both are expected to participate in the six-day tour of western Switzerland.
The tour will begin with an urban prologue in Martigny, before a stage that takes the racers up the Swiss Alps, through ski stations Chateau d'Oex to Gstaad and the Pillon pass (1 546 metres) before arriving in Leysin (1 318 metres).
They will be followed by stages through Romont and Neuchatel before a time trial on day five.
Racers will travel 164.6 kilometres to finish in Geneva in a stage that will take them up the Mollendruz (1 180 metres) and Marchairuz (1 447 metres) passes before a largely flat end along the shores of Lake Geneva into the city.