Alistair Johnston hailed team-mate Daizen Maeda as a "machine" after the Celtic forward capped a fine performance with the third goal in a 3-0 Scottish Premiership win over Livingston.
Brendan Rodgers' men were ahead through a Reo Hatate penalty when Joe Hart was sent off for a foul on Mo Sangare.
However, Celtic extended their advantage through Matt O'Riley before claiming a third from Maeda in stoppage time.
Johnston hailed the Japanese international as an inspiration for his tireless running.
"He's a machine. That's the simplest way to look at it," said the Celtic fullback.
"You look back at the Rangers match and he was just flying around the pitch for 90 minutes and it was the same in this match as well. He's got an unbelievable engine.
"He's a nightmare to play or train against. Just ask any of our fullbacks who have to go up against him. He's just constant.
"He's like this every day, which makes it really difficult for us, although it's good to train against a guy like that. You can never take a minute off."
Livingston manager David Martindale praised Celtic's performance and rubbished the notion that they have not been as good since Ange Postecoglou left the club to join Tottenham.
"I watched them on Tuesday (in the Champions League against Feyenoord) and I thought they were fantastic in the press, trying to get the ball back," he said.
"There have been a few things floating about 'they are not the same' or 'they've not clicked', but I think you saw a wee bit of a change with the Champions League and then today.
"I think they showed true character and true spirit when they went down to 10 men. But we shoot ourselves in the foot by giving away a really avoidable second goal. When I look at all three goals, they're really avoidable."
Australian Associated Press