An NBA executive says Miami Heat small forward Jimmy Butler “can ruin your whole deal if he’s not happy.”

As part of a sign-and-trade deal between the Miami Heat and Philadelphia 76ers, Butler signed a four-year, $141 million deal with the Heat.

Butler has a reputation as a locker room chemistry killer and had issues with the Chicago Bulls and Minnesota Timberwolves.

“You add Jimmy, you better be sure,” the exec told Keith Smith of Real GM. “I bet Spo (Erik Spoelstra) and Pat (Riley) are sure. And they are probably right. But that dude can ruin your whole deal if he’s not happy. And when has he ever been happy?”

Jimmy Butler is one of the best two-way players in the game. Nonetheless, he can be a hard player to get along with.

The Heat are confident Butler will be on his best behavior in South Beach since he's playing for Pat Riley and Erik Spoelstra.

Miami gave up combo guard Josh Richardson in the Butler deal. Heat fans are hoping the Butler addition works out, otherwise they lost Richardson for nothing.

This past season with the Timberwolves and Sixers, Butler averaged 18.7 points, 5.3 rebounds and 4.0 assists while shooting 46.2 percent from the field, 34.7 percent from beyond the arc and 85.5 percent from the free-throw line.

The Heat missed the playoffs last season, but they are expecting Butler to lead them back to the postseason in 2019-20.