Kevin Sheehan entered the sports-radio business because he wanted to do play-by-play.

His stab at that career path started about a decade ago, when Sheehan called a handful of Division III football games over the Internet. It peaked this month, when he was unexpectedly asked to broadcast several Maryland men’s basketball games – including Saturday’s upset of Duke — for the Terrapin Sports Radio Network.

“It’s a ton of fun, and it’s easy to do it when you’re calling a team that you’d be watching every night anyway,” Sheehan told me Tuesday, as he drove to the airport for a flight to Boston before Maryland’s game at Boston College. “I’m having a blast.”

Sheehan filled in for Johnny Holliday twice during Maryland’s non-conference schedule, when the Terps broadcast icon had conflicts, including the funeral of former football coach Joe Krivak. And with Holliday under the weather this month, Sheehan was asked to fill in for Maryland’s trip to Virginia Tech, followed by home meetings with Virginia and Duke.

Holliday — who had never missed a Duke game — was feeling better by Tuesday and is expected to be fine for Thursday’s coach’s show and Saturday’s game against Clemson; Sheehan said he was happy just to keep Holliday’s seat warm.

“I mean, Johnny is a legend. He’s an institution,” Sheehan, 48, said. “I’ve listened to him since I was a kid, and he’s been synonymous with Maryland football and Maryland basketball since the late ‘70s and early ‘80s. So yeah, of course it is [daunting], and it’s an honor. I don’t want to screw it up.”

That Sheehan would be the man calling what might have been Duke’s last trip to College Park would have seemed improbable, to say the least, when his broadcast career started. Around the time Sheehan sold his Internet grocery business to Ahold (the parent of company of Giant), he saw an ad for the play-by-play job at Catholic University. He put together a highlight reel, featuring his Division III broadcasts and a snow-delayed Maryland football game he called by himself into a recorder.

He used a few high-profile broadcasters as references: his close friend Scott Van Pelt of ESPN, and Wizards television voice Steve Buckhantz, whom he worked for at WTTG after college. Sheehan also reassured then-Catholic AD Bob Talbot that he had been doing radio for years.

“Ok, you’ve got the gig,” Sheehan recalled Talbot saying.

“How much does it pay?” he then asked.

“Nothing,” Talbot answered.

“Great, sign me up,” Sheehan said.

That position helped land him a spot at ESPN 980 doing weekend updates. After two weekends, the morning updates anchor went on maternity leave, and never came back. From there, Sheehan became a regular voice on Tony Kornheiser’s 980 show, before eventually getting his own mid-afternoon slot.

With his radio career now humming, Sheehan made it clear to Terrapin Sports Marketing – which oversees Maryland’s radio broadcasts – that he would be thrilled to help out if Holliday ever had conflicts. When Krivak’s funeral cropped up this winter, Sheehan finally got that chance.

“The truth is, when you’re doing a game with Chris Knoche and Walt Williams, it’s really easy to do,” he said. “I’ve done Catholic basketball games by myself, I’ve done George Washington basketball games, I’ve done football games by myself. That’s much, much more difficult. You’ve got to talk non-stop. When you’re doing a game with Knoche and Walt, it’s almost a conversation as much as it is calling each dribble, each pass, or each shot.”

Sheehan said he had no additional nerves or adrenaline for Saturday’s Duke game, although tens of thousands of fans would later hear his highlights on ESPN Radio and on the Maryland Athletics YouTube channel. Still, calling a Terps victory over Duke for the school’s official radio network is quite a step up from doing play-by-play for a snow-delayed football game to nobody but yourself.

“I don’t think there’s a better sports atmosphere in this city than a big Maryland game at Comcast center. It was ridiculous, as good as it’s ever been,” Sheehan said. “A lot of this stuff has been so much fun, but that was a blast. That was a blast.”