The Old Firm duo recently renewed their long-standing rivalry, with Gers getting the better of the Hoops in a penalty shoot-out in the Scottish Cup semi-final after the score finished 2-2 after 120 minutes.
Despite not possessing brilliant squads with outstanding quality, the Glasgow duo are heavily backed by huge numbers and ultimately put a number of Premier League clubs to shame.
Souness has not given up on the dream of seeing either Celtic or Rangers competing with clubs south of the border, and he believes they would be right up there with the best if they did.
“Even now, we'd have been in the top four. If Rangers and Celtic were in the Premier League today, the stadiums would not be big enough,” Souness explained to the Telegraph.
“Can you imagine Man United, Arsenal and Liverpool coming up up to Ibrox and Celtic Park? I pray it will happen one day. We talk about the global game now. They are two ridiculously good football clubs stuck in Scotland.
“How far can they go in the present set up? You won't attract the very best players while they're there. I don't think the chance has gone. Look at where the Premier League has gone in the last 15 years.”
While the Scottish duo have huge support, the same can be applied to Newcastle United and Sunderland who both have struggled at the wrong end of the Premier League table for a number of years.
The potential would be there for either Celtic or Rangers to challenge the Premier League’s so-called big clubs, but only by virtue of wise investment and good decisions both on and off the pitch.
The duo would be a welcome addition to the top flight, but the implications of them leaving Scottish football in general could have a detrimental effect where other clubs ultimately suffer.