GIF: You wouldn't like Tim Duncan when he's angry

Tim Duncan is probably the last NBA player to wear his heart on his sleeve.

But against the Miami Heat on Thursday night, Duncan exhibited a rare moment of rage that may be the angriest we've ever seen him throughout his 17-season career.

[Courtesy: Reddit user "8BitSports"]

The reaction was the result of being called for over-the-back foul on an offensive rebound. Or maybe Duncan just had a sudden flashback to Game 6 of last season's NBA Finals.