NBA commissioner David Stern will not approve any deal that involves a player-head coach trade, putting the simmering trade talks between the Los Angeles Clippers and Boston Celtics on ice.

Stern said Thursday the league wouldn’t accept the deal, even if split into two parts, because they identify Doc Rivers as the centerpiece.

“I would say: in the language of diplomacy that the teams are aware that the collective bargaining agreement doesn’t authorize trades involving coaches’ contracts,” Stern said. “The only consideration that can be done here in player transactions is other players, draft picks, and a very limited amount of cash. But coaches contracts don’t qualify as extra consideration, or acceptable consideration in player transactions. The teams know that. It has been confirmed to them.”

Stern cited the NBA’s collective bargaining agreement, which prohibits trading a player for a coach and “side deals attached” to trades are also prevented by NBA rules.

The Los Angeles Times reported the Clippers were trying to makes tweaks to the deal, all while interviewing Indiana Pacers assistant head coach Brian Shaw.

Stern told ESPN Radio Thursday the Celtics and Clippers had been notified the proposed trade, which would’ve sent Kevin Garnett and Rivers to the Clippers for DeAndre Jordan and multiple first-round picks, was not permissible.