Federer turned professional back in 1998 but did not win his first ATP title until the Marseille Open in February 2000.
That victory came in three sets, against Rosset coincidentally, a fellow Swiss professional to whom Federer attributes some of his early success.
“I knew I would never meet maybe [Stefan] Edberg or [Boris] Becker, unless I ball‑boyed them in Basel,” Federer said.
“So from that standpoint, it was so far‑fetched for me that it was just kind of good to have those people.
“Coming on tour I think Marc Rosset was important for me.
“We had a difference of 10 years.
“He explained where to book practice, how to play against certain guys, which tournaments to play maybe, all these kind of things.
“So for me he was important in my early days, besides my coach and my entourage, which was quite small in the beginning.
“But clearly if you have a hero from your country I think that could only be helpful, in my opinion.”
Federer himself has become a hero for tennis fans around the world with his 98 career titles, 20 of which have come at Grand Slams.
And the 37-year-old has revealed that he has become a mentor even for fellow players on the tour, including Grigor Dimitrov.
“I had some advice, because he came to me in 2016 at some point,” Federer added.
“He was having all sorts of issues.
“We were just having a simple conversation.
“I’m happy he took some things onboard.
“He seemed to turn it around somehow.
“He brings different things to the table because of the way he plays.
“Not many guys can do what he can do.
“He might be similar to me, but I was similar to Pete [Sampras], too.
“I always told people, ‘I’m not Pete Sampras. He’s not me. He is his own guy. He’s his own identity. Different character.’
“Just because he played with Nike and Wilson like I did with Sampras doesn’t make us in any way the same.
“I think you got to give him that, please.”