“It’s been a pretty interesting trip, that’s for sure,’’ said Russillo, a Martha’s Vineyard native. “It is odd that getting a break in this business felt like it was taking forever, and having something happen at ESPN felt like it was taking forever. But once things started happening, it felt like they all happened very fast.’’

There hasn’t been much conventional or predictable about Russillo’s ascent to his current pair of plum jobs at ESPN. Since July, he has been cohost of ESPN Radio’s “The Scott Van Pelt Show,’’ which airs weekdays from 2-4 p.m, and he is in his second season as host/ringleader of ESPN Radio’s marathon version of “College GameDay,’’ which runs from noon-7 p.m. on Saturdays.

After graduating from the University of Vermont in 1997, Russillo spent time broadcasting baseball games for the Double A Trenton Thunder before trying to find his niche in sports radio and television in Boston.

He very nearly stopped before he got started. While pursuing an on-air possibility at WWZN “1510 the Zone’’ early in 2003, he got his foot in the door . . . but only made it to the lobby.

“I tried four times,’’ Russillo said. “Every time, they said [program director] Mike Kellogg would meet me, and it never happened. Finally, I said, ‘I’m not leaving until he comes out,’ and he still didn’t come out.

“The ironic thing is, at that point, I said, ‘All right, this isn’t going to work,’ and I was ready to go home to the Vineyard and work construction with my dad. Just as I was about to leave town, I happened to go to the Harp [a bar on Causeway Street] with a friend. I saw Mike sitting at the bar, and because I really just wanted to know what was up more than anything else, I went up to him and said, ‘What’s the deal with blowing me off?’

“I really had nothing to lose. He agreed to let me fill in on a Saturday show, and it kind of grew from there.’’

Russillo, along with cohosts that included Kevin Winter, Jon Anik, and Anthony Pepe, hosted WWZN’s “The Die Hards,’’ which ran in the afternoons from mid-2003 to 2005. The program, with the articulate Russillo as its fulcrum, stood as proof that entertainment and sports knowledge aren’t mutually exclusive. It drew a small but loyal audience, appealing to a listenership that craved an alternative to WEEI’s transparent faux argument of the day. But after nearly 600 shows, WWZN pulled the plug that October and laid off a number of employees. Russillo was among those let go.

So he did all he could to stay in the game locally. He contributed as a studio analyst on Celtics programming on Comcast SportsNet New England (which he will continue to do on certain Sundays this season), was offered a backup/weekend role at WEEI (“They told my agent I wasn’t ready for more than that,’’ Russillo says), and made some inroads at ESPN as a fill-in on overnight and weekend programming.

It was a brief, unfulfilling experience with ESPN’s local radio outlet, WAMG 890, that led him to decide that working for the mothership would be his aim.

“[WAMG] hired Michael Felger over me to host [their drive-time show], which I understood,’’ Russillo said. “He was the bigger name. But at one point they brought me in for a month straight with Felger to see how we meshed or whatever. When the month was up, they decided not to keep me around because they didn’t want to pay me any money.

“It sort of soured me on the whole Boston thing at that point, and so whenever ESPN called, that immediately became the priority no matter what.’’

There was something else that soured Russillo on Boston for a time. In 2005, he was added to the revamped Patriots pregame and postgame shows on WBCN, a promising gig. But not long after he started, he was finished.

A conversation with WEEI host John Dennis’s daughter in a Boston bar for some reason inspired Dennis to leave him a voice mail - the tone being either threatening or hilarious, depending upon your perspective. The message, in which Dennis sounded considerably less polished than he does on air, became a local Internet sensation.

Not long after that, Russillo was relieved of his duties on the Patriots programming. He said he remains “100 percent convinced’’ that Dennis, who is friendly with the Krafts, persuaded them to let him go.

It may have been an accidental blessing. Not long after the incident brought him unwanted notoriety here, he began gaining in-house acclaim at ESPN for his work ethic and versatility, among other attributes.

“I just kept showing up,’’ Russillo said. “And I was relentless, persistent, and annoying as hell. I’d ask if I could fill in on ‘Mike and Mike,’ and if they let me do that, I’d ask if I could fill in for Colin Cowherd, and so on. I took whatever they’d give me, and I’d ask for more.’’

And for once, he was in the right place at the right time. During one of his various gigs, he caught the attention of Van Pelt, the easygoing “SportsCenter’’ anchor.

“The minute I heard him, I listened and I stayed listening,’’ Van Pelt said. “In this business, that’s the best endorsement you can give.’’

When Mike Tirico, the “Monday Night Football’’ play-by-play voice, decided to leave his midday ESPN Radio show this May because of time constraints, his cohost, Van Pelt, took over. He knew immediately whom he wanted for his cohost.

While there was skepticism among some in ESPN management that Russillo wasn’t a big enough name, he got the job, and even those who once pretended not to know his name by now have noticed his success. But with “The Sports Hub 98.5’’ emerging as a challenger to WEEI’s supremacy, the question must be asked: Would he ever consider coming back to Boston?

“I went to school here, lived and died with the teams here for 30 years, and at one point I wanted to stay here forever,’’ Russillo said. “But ESPN is where I want to be. I’m having the most fun I ever had. I mean, 1510 was fun when we were on air, but it was not fun thinking, ‘This place could close any day.’ It’s nice to have the security of this.’’

Chad Finn can be reached at finn@globe.com.