For the past couple of months, it has been rumored that the days of “Mike and the Mad Dog” sports talkshow on WFAN-AM (660) were coming to a close.

The rumor became reality Thursday when the station announced that Chris “Mad Dog” Russo is leaving WFAN. Mike Francesa will be the sole host of the program that is on from 1 to 6:30 p.m., and is simulcasted by YES. For a time a couple of years ago, WROW-AM (590) carried the show.

The duo had been together since September 1989.

“Mike and Chris pioneered the genre more than 18 years ago, and have shaped the sports talk format into what it is today,” WFAN operations director Mark Chernoff told Newsday on Thursday. “We wish Chris nothing but the best, and look forward to all that Mike will do in a role in which he has excelled at for years.”

It will certainly be strange not hear Russo on the show. And it will be interesting to see how Francesa handles being a solo host.

Kudos to Newsday TV columnist Neil Best, who first reported June 22 that the duo would be breaking up. He was on top of the story every step of the way.