The four-time Tour de France champion is out of this year's edition after Froome had a high-speed tumble while preparing for the time trial stage at the Criterium du Dauphine race.

Froome's accident has sent shockwaves through the sport and completely alters the dynamics around who will win the July Tour.

Porte, who has crashed out of the last two editions of the Tour, said he felt for Froome and his family.

Froome has needed surgery after suffering a broken leg, elbow and ribs.

Porte suffered a fractured pelvis among other injuries when he crashed out of stage nine at the Tour two years ago and had a broken collarbone in last year's edition - also during stage nine.

"It's not nice. Whether he's a rival or not, and no matter what people think of Chris Froome, he's still got two young kids and a wife at home," Porte told the cyclingnews website.

"There's a very human element to that. No one likes seeing anyone getting hurt."

Porte also backed Froome to return to top form.

"Whatever anyone wants to say about Froome, he's one of the hardest guys out there," Porte said.

"How he trains and how he is, you can't rule him out."

While Froome and Porte are long-time friends, their relationship took an interesting twist at the Dauphine two years ago.

Porte was unimpressed when Froome and other rivals isolated the Australian on the last stage, ensuring he would lose the overall lead.

While Froome now faces an indefinite recovery, Porte is showing signs of life after the start of his European season this year was plagued by illness.

Porte finished 11th on the time trial stage at the Dauphine - he was a team car when he was told about Froome's crash - and is 12th overall.