The Tasmanian remains highly motivated to race but sees his role evolving beyond what he admits is his final Tour as a team leader.
"I know I can still win races like the Tour Down Under and Paris-Nice but that I am also passing that window as an athlete," he told Murray Wenzel of the AAP.
"Next year I'll be 36, so I think my best days in a long race are behind me and naturally you do look at taking on a different role."
Porte says the delay to the Tour de France is complicated for two more reasons.
"It's terrible; our first son was born days before I had to fly and race the Tour de Suisse and I thought we'd nailed the timing this time, but now we have this."
"You don't want to miss the birth, but it's just something you have to do and it's probably going to be my last Tour (as a team leader)."
"I'm up for contract this year too, it's a tough year to be up and the pressure gets to you more when you have a wife and a couple of kids.
"I have had a couple of nasty accidents now and it's always at the back of your mind, you have these responsibilities.
"But it's (the Tour de France) the biggest goal and the biggest sacrifice I'd ever have to make is not being there (for the birth), so of course I'm motivated to do well."
The Trek-Segafredo rider said he is still super focused on the Tokyo Olympics road race.
"I wouldn't say my last Olympic experience was my best memory; ending up in a hospital and that started a bit of a streak for me ending up in hospitals after big races," he said.
"It was a big motivation this year, but it's back of mind again just because it's so far away.
"I can't get ahead of myself, but it will be a big motivation and when you do represent your country you don't just want to turn up for the tracksuit."
The Monaco-based rider did not relish racking up 1,000km most weeks on his balcony during lockdown.
"We're lucky we've been mostly shielded (here) but I can see Italy from the balcony 16km away and we're surrounded by France," he said. "It's strange times, and stressful especially with a pregnant wife."
"I don't think I've ever done a 1000km week sat in one place before, and we've watched all the junk TV," he said.
"I'm not going to lie, having the technology (like virtual riding app Zwift) is great but it's still pretty hard on the head.
"Once we are out on the road again, the planning with the team will start and that's what you get paid for isn't it? To be ready.
"So I guess that's all you can do."