McPhee walked out on the Bombers after last season so he could be picked up by Fremantle in the pre-season draft.
"It will be icy and cool but that's natural. When players leave clubs, often the reception they get when they come back is not very favourable," Knights said on Tuesday.
"It's a man's game and it will all be part of the theatre."
Knights again threw this support behind the Bombers' game plan despite the fact they were unable to sustain it against Geelong on Friday night, allowing allowed the Cats to run away to a 31-point win.
"It's good the expectations are going up on this group, that we've been critiqued pretty hard after a performance against the reigning premiers," he said.
"For two-and-a-half quarters we had the balance right and we were really diligent both when we had the ball and they had it. The reality was, we couldn't keep it up.
"Fast football is sustainable. I don't think you're going to win a premiership by playing slow, economic football. That's our belief here."
In selection news, Mark McVeigh will come into the side after serving a one-match suspension while Jay Neagle is available despite tweaking his ankle against Geelong.
Knights said he was not expecting to tinker too much with the side but was pleased David Myers, Michael Hurley, Nathan Lovett-Murray, Bachar Houli and Sam Lonergan were applying pressure to the senior line up.
He said the Bombers would have to be at their best to beat Fremantle this week after its "formidable" display against Adelaide on Sunday evening.
"We acknowledge the way they ran through the lines. It was certainly a big upside in their game," he said.
"To ... have a comprehensive victory against [a team like Adelaide] is a great result."
Knights said the Bombers were not surprised to have David Hille available after his charging report from Friday night was thrown out by the match review panel.
"It was pretty clear his intention was to go for the mark. We thought there was a decent chance that would be the case and thankfully it went that way," he said.
"We're really pleased to have him out there because we thought in his first game last week he played well and he got back into the swing of AFL footy pretty well."
