The Vuelta resumes today with five stages remaining in the final grand tour of 2013.
"The Vuelta has been super for us," Riis told ekstrabladet.dk. "It has been a success."
Nicolas Roche, with a stage win and the race lead on stage 8 already to his name is currently sixth overall, 3:43 behind race leader Vincenzo Nibali (Astana) and as far as Riis is concerned, the Irishman’s race is far from over.
"I certainly think that we still need to go for GC," he stated. "One can never know what happens. We are in the last week, and people start to get tired. Suddenly the podium might be within reach again. We must believe that.
"There is also an opportunity to ride for stage wins. It'll be the people who have tried in recent days – [Rafal] Majka, Chris Anker, Oliver Zaugg and of course Nicolas Roche."
Riis maintains that Nibali is still the man to beat but the Dane does not believe the Astana rider will have it all his own way, with Chris Horner (RadioShack Leopard) 28 seconds in arrears, and with Alejandro Valverde a further 46 seconds back.
"There will be war. It has probably given the others a feeling that Nibali was in crisis on Monday, I think there was attacks coming from everywhere," predicted Riis with Nibali losing time to his rivals during stage 16, unable to keep pace with the attacks in the final three kilometres of the stage.
"If Nibali continues in that way from Monday, it may well be that Chris Horner can go past him," said Riis.