MIAMI — As Miami Heat guard Jimmy Butler finishes tearing through the plastic wrapping, he immediately opens the fresh deck of cards and says the “janky” ones must go.



He has no use for the “Wild Shuffle” or “Wild Customizable” cards when playing UNO, his favorite game. They have no purpose, he says, sliding them across to the other end of a table that sits just outside the team’s practice facility.



Butler then begins to shuffle like the calmest of Las Vegas blackjack dealers. If you think he is intense when in a defensive stance on the basketball court, just imagine staring at him while he’s holding seven cards and ready to do everything possible to defeat you in a game recommended for kids between the ages of 2 and 10. On Monday, after a two-hour practice, Butler agreed to The Athletic’s best-of-five challenge in one of the world’s most popular card games.



Actually, he accepted by saying,...