Charles Barkley Interrupts Kenny Smith After Jay-Z Reference, 'Not a Good Time'

Things got awkward on the "Inside the NBA" set on Tuesday ... when Kenny "The Jet" Smith innocently name-dropped Jay-Z in the middle of a segment -- which prompted Charles Barkley to admit it's "probably not a good time" to bring up the rap legend in conversation.

The moment happened when Shaquille O'Neal, Ernie Johnson and Chuck were weighing in on TV personality Stephen A. Smith's public free-throw contest challenge to Smith ... to which he scoffed at, saying the ESPN talent isn't on his level.

Smith started to make his case by saying entertaining the notion would be like Jay-Z getting in a rap beef with a no-name MC ... but before he could finish his thought, Chuck interrupted.

"Probably not a good time right now," Barkley replied.

Naturally, the guys on the desk couldn't control themselves ... and Shaq even got up and walked off the desk as giggles leaked out of the whole crew.

Smith then got back on track ... adjusting his analogy to Kendrick Lamar instead of Hov, but the damage was done.

While the TNT guys had their laughs, the allegations against Jay-Z are serious ... but the Roc Nation founder has adamantly denied any wrongdoing and claims it's a "blackmail attempt."

Chuck, Shaq, Ernie and Kenny are known for their iconic dialogue on the show ... but after Tuesday's show, it's apparent some things are off the table -- even if they navigate through it in their own way.