The Cleveland Cavaliers were up big against the Atlanta Hawks midway through the third quarter Saturday night, so LeBron James decided to sub himself out.

There was just one problem -- you're not allowed to do that.

Richard Jefferson tried to check himself in before the referees noticed the teams were playing four-on-five basketball, but it didn't work. And the Cavaliers were assessed a technical foul as a result.

Confused about this rule? Glad you asked. ESPN's Dave McMenamin tweeted out a link to the explanation.

The Cavs won the game 109-97.

Thumbnail photo via Ken Blaze/USA TODAY Sports Images