"Why would you rush when you've had 14 hours to get ready?" he shouted.
Thankfully for most of the home crowd inside the O2 Arena, Murray didn't put them through a marathon roller coaster like his previous win against Kei Nishikori, a three-set epic that was the longest three-set match in Tour Finals history.
Here he was far more composed and did what he needed to do early by winning the first set, guaranteeing his place in the season-finale semifinals for the first time since 2012. Murray wasn't about to put his feet up, though -- he went on to beat Wawrinka 6-4, 6-2 and equalled his career-best win streak of 22 matches.
"Stan's one of the best players in the world," Murray said on court. "When he plays his best tennis, he's unplayable. When the ball was there to be attacked I did it. I played a very solid match."
He has won four titles in that time and dropped just five sets, his ruthless consistency taking him to the No. 1 ranking for the first time and dethroning Novak Djokovic after 122 consecutive weeks.
The two men remain on course to meet in what would be a dream curtain closer Sunday -- it would be the first time in the history of the Tour Finals where the two finalists would not only be playing for the championship but the year-end No. 1 ranking.
"I don't think it should have too much of an impact," Murray told a news conference.
"Thankfully today's match was quick. In the match with Kei, I played three hours and 20 minutes. Definitely would have had an impact on the next day's match. Luckily I had a day's break after the match with Kei."
Djokovic will face Nishikori Saturday -- the Japanese player was already guranateed a semifinal spot before losing to Marin Cilic 3-6, 6-2, 6-3 Friday evening, their match rendered a dead rubber with Murray winning in straight sets
Wawrinka had qualified from his group for the last three years, and the equation was simple for him Friday -- win or he was definitely going home.
Murray guaranteed he would be hanging around for the weekend when he took the first set in 48 minutes.
Wawrinka made him fight for it -- the US Open champ saved three set points at 5-3 down. Wawrinka had made a fearsome start, too, hitting Murray off the court the first few games, the Scot's timing still not right at the O2 Arena.
"I weathered the early storm a little bit," said Murray. "Stan came out hitting the ball huge. He was hitting a lot of winners, a lot of aces. But once I got through the early part of the match, I started to create chances in most of his service games."
The momentum changed when Murray took the first break point of the match in the seventh game of the opening set. Wawrinka could only slam his racket down in disgust.
Wawrinka possesses the firepower to blast anyone off the court but his defence is not up to Murray's level and the unforced errors started to flow -- 26 for the Swiss in total over one hour, 26 minutes.
The most drama Murray faced in the second set, in which he raced into a 4-0 lead, was when he broke a string serving for the match at 5-2.
"The first set was tight, there weren't really many chances either way," Murray added. "The second set I'd already qualified. Stan needed to win so it was a bit easier for me to player freer than him."