Former Parkhead striker Donnelly feels Brown could mentor McGinn before handing over the mantle in the future.
“I’m surprised that Celtic didn’t have a sniff at him in the January transfer window, and I wouldn’t be surprised if he ends up there,” Donnelly said of the Hibs player who is contracted until summer 2019.
“Scott Brown still has a lot to offer there, and with him retiring from Scotland, I can see him playing on there.
“But who better to go in and learn from playing alongside than him? He’s that kind of player, he has that aggression, he’s tenacious and he can play a bit.”
Donnelly feels McGinn has been an outstanding performer this season and has already shown he has what it takes to cut it at Celtic Park, where his grandfather Jack was once chairman.
Donnelly said: “I’m surprised Celtic haven’t gone for him yet, and he has the mentality to handle it.
“He scored two in the draw at Celtic Park, he was one of the better players when they came the last time, and he scored when they won at Ibrox.
“If you can go in there and handle yourself in those environments, you can handle yourself anywhere.”
Donnelly feels McGinn would be a natural fit with Stuart Armstrong and Callum McGregor and they could be a unit for Celtic and Scotland for years to come.
He said: “I think we should be building the Scotland team around these guys. McGregor and John McGinn for me have been the two best players this season in midfield.
“I know that Alex McLeish was experimenting on Friday night, but I think we should build the team around the likes of McGregor, Armstrong and McGinn.
“I think that’s a really exciting and creative midfield going forward for Scotland, and they are all relatively young.
“McGregor’s excelling at it at the moment. He’s one of the top men.
“I said earlier on in the season that he’s one of the first names on the team sheet. He had a little dip, but now he’s back.
“They are the type of players that if we can get them firing for Scotland, it gets me excited about the qualification group.”