Of course, Reirden was the Caps' head coach from 2018 to 2020 ... and was canned after Washington lost in the first round of the playoffs for 2 consecutive seasons.

Now that Reirden has a new gig as an assistant with the Pittsburgh Penguins, the coach is parting ways with his 6-bed, 8-bath, 6,352-square-foot Virginia pad.

The crib comes with an industrial chef kitchen, rec room, home theater, exercise/game room, and a walk-in wine cellar.

The owner's suite comes with all the bells and whistles ... including walk-in closets, gas fireplace and surround sound speaker system.

The outdoor area is decked out with a heated pool, kitchen and bar, cabana house and a playground that looks like any kid's dream come true.

The house was listed by Jordan Stuart of Keller Williams Capital Properties for $2.25 million just days ago.

And, if ya can't make it in person ... check out the virtual tour.