The Frenchman will face Team Sky's star at the Tour again starting on July 7. Froome won last year, but since has been dogged by an asthma drug case.
"If I were in his position, I would just not consider starting the Tour de France and I would be ashamed to be linked to such a case," Bardet said.
Bardet spoke in a longer interview with Belgian newspaper Het Nieuwsblad. He is racing this week in the Critérium du Dauphiné, but the attention since last December has been on Froome's case.
Team Sky's star tested over the limit for asthma drug salbutamol after the Vuelta a España's stage 18 on September 7, 2017. Froome and Sky deny any wrongdoing, and have been preparing a legal case since the results came out to try and clear his name and to avoid a suspension, as well as the loss of his Vuelta title.
And as he has a right to do, Froome continues to race. Rules for specified substances differ from others that draw immediate bans, with the UCI's own rules allowing for riders to race in such a case.
Froome came from behind to win the 2018 Giro d'Italia in spectacular style in May with an 80.3-kilometre solo attack. As the applause sounds, so do the critics.
"But everyone reacts differently and the fact is that the rules allows Froome to line up in the race," Bardet said. "Everyone, including him, wants this case to be settled quickly."
Froome's other rivals have also said that they would sit out in a similar situation.
"That's not good for cycling," said Tom Dumoulin (Sunweb) before placing second to Froome in the Giro. "Everybody would like it not like this, including Chris Froome, to be starting the Giro with doubts or uncertainty."
He added that because Team Sunweb follows stricter rules, "I would not be [racing]," and that he preferred it that way.
This week, UCI president David Lappartient reminded everyone that the rules must be followed.
"My point of view has always been that the best thing would be if he does not take part in competitions. But he decides to race. We respect his right," Lappartient told Le Parisien.
"This case is much more complex than others. And perhaps he has more means to demonstrate this complexity precisely, where others might have given up for not being able to carry out more cumbersome procedures.
"My wish has always been that it would be judged before the Giro d'Italia – and that couldn't happen. Now, I would like it to be settled before the Tour de France. Well, you have to be realistic. I think that won't happen."
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