An explanation of the appeals board's decision to overturn Maxwell's suspension is expected this week after the tribunal and appeals board ruled differently in the case.
McPharlin said it would be nice to have a black and white ruling for bumps, but the nature of football meant there would always be grey areas.
"It's a little bit confusing for players at this point with that result," he said on Monday.
"You can't really do a lot of thinking out there, a lot of it happens quite instinctively.
"I think you just need to appreciate that you need to protect the head at all times. That's the message that they're trying to portray but it's certainly difficult at times.
"I'm not going to think about it too much, but you just hope you don't get caught up in a situation like that."
Fremantle travels to Manuka Oval to face North Melbourne this Saturday, but McPharlin was unsure if he would make the trip.
After a pre-season that he says has been been 30-40 per cent more productive than previous years, the versatile defender said preparation for the round one clash with the Western Bulldogs was now the priority.
"I've done a fair bit of training and played a couple of games already," he said. "Obviously it's about preparing for round one so that decision will be made later in the week for me.
"[My pre-season] has been well managed I think, with my very fragile body.
"I think [the improvement has come with] maturity and experience and knowing how to manage your body through sessions, combined with a smarter program and just being able to get through the majority of it without having to pull out."
McPharlin said captain Matthew Pavlich and Chris Tarrant trained well on Monday morning and should make the trip to Canberra, with Tarrant expected to play in defence.
"I'm very excited to see how he takes on the position in defence," McPharlin said.
"When you're a forward and you go back you certainly know what can irritate a forward, so he's going to take all that experience and he's been pretty good so far.
"We'll rotate on the bigger type forwards, but I think predominately I'll be deeper than he will be, but we'll see how the season unfolds."
