Tour de France winner Alberto Contador and the Tour of Spain runner-up Ezequiel Mosquera were suspended for suspected doping on Thursday in a devastating blow to cycling's battered image.
The suspensions set back the sport's efforts to restore its credibility after a string of high-profile drugs cases.
"It tugged at my heartstring when I heard the news (about Contador). Such scandals don't do the sport any good. Especially for the sponsors, who try to avoid such bad publicity," Francis Lafargue, head of communications at Team Caisse d'Epargne, told Reuters.
Contador, one of the biggest names in cycling, tested positive for a "very small concentration" of a banned anabolic agent and was provisionally suspended, the sport's governing body, the International Cycling Union (UCI), said.
It added in a statement that the Spaniard, who won his third Tour this year, was tested during the second rest day of the highest profile race in the cycling calendar.
Contador, regarded as one of the sport's greatest ever riders, vehemently denied doping, telling a news conference that contaminated meat was to blame for the positive result.
Shortly afterwards, the UCI revealed that Mosquera, second in another of the sport's blue riband races, the Tour of Spain, had also tested for a banned substance which helps increase blood volume delivering oxygen to the body.
His Xacobeo team mate and fellow-Spaniard, David Garcia Da Pena, failed a test for the same substance, hydroxyethyl starch, the UCI said.
Contador's news, however, was by far the bigger blow to cycling and its most famous race, with a second B test confirming the presence of clenbuterol, a banned steroid.
"The rider, who had already put an end to his cycling season before the result was known, was nevertheless formally and provisionally suspended as is prescribed by the World Anti-Doping Code," the UCI statement said.
Contador, who is leaving Astana to join Bjarne Riis's Saxo Bank team next season said he was "sad and disappointed" and the case was "a genuine mistake."
"It's such a small quantity that it's impossible to ingest or administer to yourself and in terms of performance, it doesn't help at all," he said.
"I won't allow something like this to ruin everything. It won't be easy but I don't think it will affect me."
Saxo Bank said in a statement: "It is Riis Cycling's hope that this case can be resolved in a orderly and timely fashion as it is in the best interests of all parties involved that the proper conclusions are drawn within a reasonable period of time.