Boston Celtics point guard. Marcus Smart is well known for his fiery demeanor on the court. It's no surprise that this apparently extends to friendly competitions off of it.

But that's what his Celtics teammates revealed after Marcus Smart sent out a goodbye message to those departing Boston via their recent Malcolm Brogdon trade with the Indiana Pacers.

Smart clowned two-time Celtics center Daniel Theis for supposedly not being able to beat him at any card game:

But Theis responded not long after with two card claims of his own. First, that Marcus Smart can't survive without an card alliance with Theis to wipe out their other card competitors on Grant Williams and Derrick White. And second, that Smart apparently stormed out of a game of UNO in a temper tantrum one time.

But of course, this could all be hearsay. That is, until Celtics forward Grant Williams chimed in to corroborate Theis's account with a message of his own. He also made sure to point out that beating him and D-White in whatever card game they played isn't as impressive as Theis was making it out to be.

It seems clear that these Boston Celtics take their card games seriously. With Daniel Theis now gone, it looks like a new seat at the card table just opened up for one of their newer acquisitions.

Malcolm Brogdon and Danilo Gallinari have long established themselves as productive veterans in this league. But their proficiency at cards – and potential to ignite a Marcus Smart temper tantrum – remains to be seen.