MacLean, host of CBC's Hockey Night in Canada, served as a referee for the final two periods and overtime of the Buffalo Sabres' 4-3 pre-season win over the Pittsburgh Penguins.
By the end of the night, MacLean, a certified referee in the Canadian Hockey Association, got into the spirit of the league standard by calling a tripping penalty on Pittsburgh veteran John LeClair with one minute to play in regulation and the game tied.
"I was a little numb on that call, not that it had any bearing on the game, but that was the call that was most foreign to me because of my instincts," MacLean said. "But I was thinking about what we're trying to do with stick fouls.
"It's a far cry from Junior B in Southern Ontario. . . . The referee is so focused on the puck, that all the other things I took for granted like positioning ... the general sense of where I am on the ice was shot. About 15 times I got caught in a position where I would never be."
In the officials' room after the game, NHL vice president Colin Campbell gave MacLean a tongue-in-cheek critique of his performance.
"You can't call a penalty with a minute left in the game," Campbell jokingly told MacLean.
NHL director of officiating Stephen Walkom, a former referee, worked alongside MacLean for the final 43 minutes of play.
"He's a work in progress," laughed Walkom. "I don't think he's one of our top prospects."