The NBA has fined J.R. Smith $50,000 for "recurring instances of unsportsmanlike conduct" following his shoelace stunts in the New York Knicks' past two games, the league announced Wednesday.

Smith untied Dallas Mavericks forward Shawn Marion's shoelaces during the second quarter of the Knicks' 92-80 win Sunday.

He was warned by the league to "refrain from further conduct of this nature" before the Knicks' next game Tuesday.

Smith was then seen Tuesday attempting to repeat the action when he reached at Detroit Pistons big man Greg Monroe's shoes while lined up at the free throw lane. That's why the league took action.

"I've never seen it done in an NBA game, put it that way, in all the years I've been around," Knicks coach Mike Woodson said before Tuesday's game.

Smith had been in trouble with the league already this season.