Speaking after finishing second in the Tour Down Under on Sunday, Porte said that he was looking forward to another crack at the Tour after crashing out in 2017, and that there would be other rivals to take on if the outcome of an anti-doping investigation into Froome means he cannot start in July.
"There's still a lot of water that has to flow under the bridge," was Porte's response when asked by French newspaper L'Equipe if he thought Froome would be able to ride the Tour de France in July.
"It will not be good for cycling if the defending champion is not there, but there will always be other opponents, starting with Romain Bardet, and Vincenzo Nibali, who has already won nearly everything."
Watch: Tour de France 2018 route guide
Froome is currently under investigation after delivering an adverse analytical finding for high levels of salbutamol at the 2017 Vuelta a España, but has not been suspended due to the nature of the substance, raising the possibility that he could race the Tour with the investigation still ongoing.
Froome has denied breaking anti-doping rules which allow athletes to take a maximum of 800mg of salbutamol per 12 hours, and, with Team Sky's backing, has vowed to clear his name.
Porte also revealed that a new addition to his family will mean that he will follow a different race programme in preparation for the Tour, racing the Tour de Suisse and Tirreno-Adriatico rather than the Critérium du Dauphiné and Paris-Nice, where he struggled in the wind and rain in 2017.
"My wife and I are expecting a baby by the end of May. To fully enjoy this moment, I will postpone my return to competition in the Tour de Suisse, which I have never ridden, and I will wait until next year to win the Dauphiné.
"I'm also changing my spring schedule. I love Paris-Nice, but after the Tour of Algarve, I want to challenge Froome and Nibali in Tirreno-Adriatico."
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