Pedrosa, who turns 38 later this month, is making his second grand prix appearance of the 2023 season as a KTM wildcard.
In the sprint race at Misano on Saturday, Pedrosa narrowly missed a first podium since his last MotoGP win in Malaysia in 2017, finishing fourth behind Ducati's Francesco Bagnaia and ahead of KTM team-mate Brad Binder.
Pedrosa retired from MotoGP at the end of the 2018 season, while Rossi carried on until the end of 2021, when he was 42.
Clearly still competitive despite his time away from racing and his age, Pedrosa says he now understands just how impressive Rossi's final victory at Assen in 2017 was when he was 38.
"Now that I'm this age, if I stop to think about the day Valentino Rossi won his last race at 37, or Loris Capirossi at 38 [ed - he was 34 when he won at Motegi in 2007], at that time I, who was very young, didn't value enough the fact that they were able to win at that age," Pedrosa said.
"Now that I have those years, I'm back racing some races and I'm fighting in front with the young guys, now I know that racing at the top level with all these years is more difficult than doing it when you're younger. No doubt.
"I can't speak for myself, but I do remember what I lived through when Valentino or Loris were winning at 38 and I didn't give it value, and now I know the value of them winning at that age."
Binder fought with Pedrosa in the closing stages of the sprint on Saturday and came close to passing him.
The South African was ultimately unable to take fourth away from the veteran Spaniard, and noted how Pedrosa "looks like he's riding at 80%".
"Tell you, looking at Dani's data, he doesn't brake early – he brakes fricking late," Binder noted.
"The last lap I tried to line him up and he had a big shake off the back straight. I had to smack the brake to not hit the back of him.
"So, I lost time and that really messed up my chance of trying to get past him.
"The guy, he looks like he's riding at 80%. It's really impressive."
