The 38-year-old veteran, with over 350 appearances in all competitions for Rangers, is known to be demanding of his team-mates on the pitch.
MacDonald, a close friend of McGregor, also came through the ranks at Ibrox with the Gers number 1, having shared a dressing room during their youth career.
And the ex-Saints hitman insists the fans have only seen one side of McGregor, who is always demanding and shouting at his backline, whereas what goes behind the scenes can only be appreciated by those who have worked along with him.
MacDonald, who gave an insider’s insight into the physical effort and determination that McGregor has put into his game from the very start of his career, believes the shot-stopper can still keep on pushing the boundaries as a he has lot left to give the Glasgow giants.
“He’s a top pro”, MacDonald told The Athletic.
“People don’t see that side to him.
“They only see the Greegsy who carries on and moans at centre-halves.
“They don’t see him in there first thing in the morning stretching and doing his gym work for his flexibility.
“He’s done that since day dot.”
Having featured in between the stick in the Rangers’ 3-2 win against Standard Liege on Thursday in the Europa League, McGregor has now become the Gers all-time record holder for the most appearances in Europe with 83 outings.
