The NHL is not a buy now, pay later operation. There's no such thing as credit where the salary cap is concerned. If you want the player, you have to have the cash. Sometimes a team can find itself with too much in its cart when it gets to the till which then results in a few items getting returned. It's the black and white truth of today's NHL.
George McPhee has been able to amass a roster loaded with talent. But talent is expensive and while McPhee has signed a plethora of value contracts, he found himself tipping the salary cap scale at a number a touch too high.
In order to get compliant with the cap, McPhee first moved Erik Haula to Carolina and took back Nicolas Roy, a younger and less expensive player. Friday, he completed a second trade, sending defenseman Colin Miller and his $3.75 million price tag, to the Buffalo Sabres and received two picks (2021 2nd round, 2022 5th round) in return.
While McPhee didn't get a roster player in return right now, he did get valuable assets which will enable him to be a buyer at the trade deadline if his team is a contender and he views the roster in need of an upgrade at a position or more.