The 23-year-old was the Pies' first substitute player under the new interchange ruling, and didn't enter the clash with the Power until Andrew Krakouer cramped midway through the final term.
His lack of match conditioning from the game meant he had an unpleasant surprise waiting for him at the Westpac Centre the following morning while the other 21 players from the match headed straight for the pools.
"I ran five or six 500's on the treadmill with not much rest in between in the altitude room as well, so I got a massive sweat up and was definitely pretty fatigued after that," he told afl.com.au this week.
"I knew it was coming as well, so I could look forward to it.
"We had to make sure I got in a bit of a run and didn't just have a weekend of doing nothing.
"It wasn't a really long session but it was pretty tough."
Macaffer entered the season opener with no idea of how the rule would see his afternoon play out considering he was the Pies' guinea pig in working out how best to manage the substitute's contribution.
After the game, Mick Malthouse revealed he toyed with the idea of leaving Macaffer on the bench for the entire game to boost the other players' game time but was forced to bring the premiership player on when Krakouer cramped.
"It was a different feeling, sitting down on the bench and not being able to go on the ground," Macaffer said.
"I was nervous sitting there waiting because I didn't know if was going to come on at all.
"Getting halfway through the last quarter, I was starting to think I wasn't going to come on at all, and I ended up getting a run for the last 10 minutes, so it was good to come on and try and get a kick."
Macaffer made sure he had a ball in his hands at all times while sitting on the pine, went for a run up the boundary "four or five times" a quarter and worked up a sweat during the breaks to make sure he was ready to go if there was an injury.
He said he noticed a considerable difference in how he felt entering round two against North Melbourne given his limited game time the previous week.
"While the boys were doing their recovery I was feeling pretty fresh and eager to go, so for round two, I was jumping out of my skin," he said.
"Coming in to training early in the week, the boys were getting massages and I was with the coaches and running on the treadmill and doing stuff I wouldn't normally be doing early in the week after a game."
Macaffer said his game time against the Kangaroos increased from around 75 per cent to 90 per cent given the lessened bench.
He also said he didn't expect to named as the Pies' substitute player again anytime soon as Malthouse was keen to ensure an even level of playing time was maintained across his squad.
Brent Macaffer is a $314,600 forward in this year's Toyota AFL Dream Team competition.
