The 29-year-old Spaniard, who was stripped of his 2010 Tour de France title and banned for two years after testing positive for the anabolic agent clenbuterol, finished with the pack in 108th position on the flat 203.9-kilometre opening stage to Middelburg.
"I had good feelings considering it was not the ideal day to start my comeback, with a stage of more than 200 kilometres, rain, a lot of wind and a flat course," the Saxo Bank-Tinkoff Bank rider said.
"My team mates protected me at all times and I think that these days will do me good in terms of picking up rhythm for the Vuelta," he added. "We have a good team and I believe we can be very successful."
Contador is hoping to be part of the Spanish squad for the road world championships in the Netherlands in September after competing in the Tour of Spain later this month.
He has always maintained his innocence of deliberate doping, blaming the positive test result on contaminated meat.