The move was not done with Bunting's play being a factor, but rather from a defensive standpoint as Kerfoot is more defensively responsible within those top line minutes. At the time, the Leafs were being swarmed by Tampa and the Matthews line was having difficulties generating any scoring chances 5-on-5 against the Cerelli line.
When asked about moving Bunting Keefe said, "You're coming into the playoffs for the first time and playing on that line, it's going to be tough, it's not easy minutes, but I think he'll continue to get better for us the more reps he gets."
At the same time, Keefe spoke of moving Kerfoot citing, "he's very responsible. He's very good at all areas of his game and that translates very well this time of year. His details and habits are good and those things don't change."
As mentioned, when the move was made the Leafs were defending the lead and Matthews was having a hard time 5on5 offensively so they became a more defensive line once Kerfoot was added. Keefe also said they plan to start with those lines tomorrow night but that they could change depending how the game goes.