Who Plays Danny's Friend Mickey On Blue Bloods & How Many Episodes Is He In?

For the better part of the past 15 years, "Blue Bloods" has regularly ranked as one of the best-loved procedural dramas on television. That, no doubt, has a lot to do with fans' continued adoration of both the family at the heart of the story and the actors who've played them throughout. They've just as often reveled in appearances from a long list of famous guest stars, including a pair of unforgettable turns from one Tom Cavanagh.

The actor made his first "Blue Bloods" appearance during Season 4, playing Michael "Mickey" Patrick, a trouble-making childhood pal of Donnie Wahlberg's Detective Danny Reagan. After a lengthy stay away from New York and his old buddy Danny, Mickey makes his way back to town, where, much to the chagrin of Danny, it seems Mickey hasn't exactly shed his trouble-making ways. As that now means Mickey is making deals with big-time mob bosses, Danny eventually does the Reagan thing and puts him in handcuffs.

Their paths cross again in Season 13 of "Blue Bloods," when Mickey resurfaces from Witness Protection to enlist Danny's help in finding his missing wife. And if you saw that episode, you know the case gets tricky and then some. Either way, Cavanagh was in top form in each of his "Blue Bloods" guest spots.

That Tom Cavanagh was so good on "Blue Bloods" is hardly surprising, as the actor has become a bit of a low-key TV all-star over the course of his career. Though most viewers were likely first exposed to Cavanagh's on-screen charms when he played the titular role in the NBC dramedy "Ed" in 1999, he'd actually been working as a professional actor for most of the '90s. As for "Ed," Cavanagh was at his charming best over the show's four-season run, which found him trading lines with future "Modern Family" star Julie Bowen and "Mad Men" breakout John Slattery, as well as Justin Long, Michael Ian Black, and Ginnifer Goodwin, among others.

Cavanagh would go on to leave his mark on another beloved series, playing the sometimes wayward older brother of Dr. J.D. Dorian (Zach Braff) on "Scrubs." The actor played Dan Dorian in seven episodes of "Scrubs," making his final appearance in Braff's own final episode. Circa 2006, Cavanagh would also portray the caring dad in the big screen adaptation of the iconic children's book "How to Eat Fried Worms."

In 2011, Cavanagh began a multi-episode arc as a pro golfer suffering from Lupus on USA's hit "Royal Pains." A couple of years later, he'd land one of his signature small screen roles, playing Dr. Harrison Wells in The CW's "Arrowverse" drama "The Flash." Wells' story was complicated over Cavanagh's nine-season run, to say the least, and the actor was a legit series' standout every step of the way.