The 37-year-old keeper announced this week that he has walked away from the national team in order to prolong his club career with Rangers.
Celtic duo Bain and Craig Gordon will benefit in terms of game time, given that McGregor had been Alex McLeish's number one during recent international breaks.
But the 27-year-old has told The Scottish Sun that he will miss the veteran stopper nonetheless.
“I saw the news with Greegsy and it’s a massive blow for the country because he’s a top goalkeeper who has been a great servant for the nation. He’ll be a big miss for us. Every time I was away with Scotland I was impressed with how good he was — his speed across the goal and also his determination not to lose goals.
“His shot-stopping ability is second to none. It was great to work with him and push yourself to be at that level as well.
"We’ll all be going in there champing at the bit to be the No 1 and play. Since I’ve come to Celtic, I’ve just viewed everything as an opportunity. This is another one I hope I can take if called upon.”
McGregor has been in outstanding form for Rangers since returning to Ibrox last summer.
The Celtic man is right - he is undeniably a huge miss, but one that McLeish's side will have to get over sharpish.
The Scots have two Euro 2020 qualifiers against Kazakhstan and San Marino next week.