Contador retired after 2017 Vuelta a España that Froome won. During the race, Froome tested for double the allowed limit of asthma drug salbutamol. The case is still ongoing and could see Sky's Grand Tour star serve a ban of up to two years.
"One thing is clear, if the authorities that rule over this sport allow him to race then it's normal that Froome is competing," Contador told Spain's AS.
"What is a pity is that it is taking so much time for this case."
Froome failed the test at the end of stage 18 on September 7, and went on to win the Vuelta a España, following his fourth Tour de France title in July. The test result only became public on December 13.
Time has passed due to the complications of the case. Froome is reportedly trying to show that his body did not manage the asthma drug well so that he somehow had high amounts – 2000, well over the allowed limit of 1000 nanograms per millilitre (ng/ml).
Once the case is referred to the UCI's anti-doping tribunal, the judge will establish a time limit for the case and give Froome at least 15 days to submit his defence. The ruling could come quickly afterwards, but a decision will likely be appealed by Froome's team in the case of a guilty verdict or by the World Anti-Doping Agency (WADA) in the case that the judge rules in Froome's favour, with a final decision made in the Court of Arbitration for Sport (CAS).
Spaniard Alberto Contador knows the process well as he tested positive for Clenbuterol in the 2010 Tour de France and continued to race. A ruling later stripped him of his results including the 2011 Giro d'Italia victory. Froome, it's understood, would not take a back-dated ban if one came and any results since the Vuelta would stand.
"They need to take a decision," RCS Sport's cycling director Mauro Vegni said last month.
"The process is too long. Every time that something happens we have to wait a year to have a decision. Maybe it's time to look into changing the rules."
Froome is one of the favourites for the Giro d'Italia, May 4 to 27, along with defending champion Tom Dumoulin (Sunweb). Contador will commentate on the race for Spanish Eurosport.
"The Dutchman is the big favourite with Froome but the Italians always manage to have an impact on this race," Contador continued.
"Miguel Angel López should be watched. The Spaniards? Marc Soler [Movistar], if he races, he can do big things. While David De La Cruz will be working for his team leader [Froome].
"The Giro is the race that I miss the most. It just feels like everything cycling should be, with an informed public and so much passion. I don't miss cycling so much, but I still continue to ride three or four days a week."
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