"So the trade is Pierre-Luc Dubois for Darcy Kuemper, one-for-one.
The Kings needed a goaltender and didn't want Dubois' contract anymore. Not sure if Kuemper really solves the problem, but well! They were probably in on the Markstrom situation and turned to Kuemper after he went to New Jersey.
The Caps, on the other hand, had a huge need at center. But PLD will cost the Caps $8,500,000 for the next 7 years, while Kuemper will cost the Kings $5,250,000 for the next 3 seasons." - Marc-Olivier Beaudoin