The beauty of making a trade in the NHL is that judgments on them are best left until later. Mistakes can haunt teams when deals don't turn out as intended. We take a look at a few trades that may leave teams rueful.

One example is the Los Angeles Kings who acquired Pierre-Luc Dubois from Winnipeg Jets but may face challenges now. Another trade involving the Pittsburgh Penguins may leave them regretting dealing Jake Guentzel to Carolina Hurricanes.