Now the pair are being linked with a partnership in management, not the midfield, and a move to take over at Aberdeen – a switch which would be a success for Brown, his old boss believes.
Glass has emerged as one of the leading candidates to replace Derek McInnes at Pittodrie, with rumours suggesting he’d take his old team-mate Brown north as player-coach, plus ex-St Mirren forward Allan Russell.
Williamson, who signed Glass at Easter Road after his release from Watford in 2003, said the pair linking up again was “a great idea”.
He said: “I signed Stephen after he’d been released by Watford. He’d always caught my eye at Aberdeen.
“Broony was established in the team when he came so I’ve no idea whether the two of them were friendly.”
And Williamson, who was last in the dugout as Kenya national team boss in 2016, told the Scottish Sun it might lead to further success and a Parkhead return for Brown further down the line.
He added: “I think Stephen and Broony teaming up at Aberdeen — if that’s what was to happen — is a great idea. I don’t think Broony is finished at Celtic but sometimes players have to leave a club in order to get back.
“I wouldn’t rule out a scenario where Scott leaves Celtic, goes away and starts his career as a coach somewhere else, then ends up going back.
“It would be an interesting path if he went down that route, he’d be better prepared if he did eventually go back.”