McCall was at the Jags helm for four seasons from 2007 to 2011, building an attractive footballing side and guiding them to a second-placed First Division finish in the 2008/09 campaign.
He watched as a media pundit in the January window as Thistle gaffer Alan Archibald signed Lyle Taylor, Chris Erskine, Prince Buaben and George Moncur all on loan and snapped up veteran stopper Lee Mair from St Mirren.
Now McCall reckons his former team can win their four-club battle for survival and, if they do, he predicts a bright future.
McCall said: "Thistle should be between 10 and 14 points better off than they are right now. They have played some fine football and just haven't been able to finish it off regularly enough.
"But I think the additions Archie has made in the January window can really help Thistle stay up. It goes without saying that consolidation in the SPFL Premiership is the be-all and end-all for the first season back up for a promoted team.
"I think that's even more so for Partick Thistle, given how long they have been away.
"But if Thistle stay up I can see them really going from strength to strength in the Premiership and developing as a team.
"They have so many talented young players, like Stuart Bannigan, who has really impressed and they will learn so much from this season. It will be the same for Archie in his first season in the Premiership as manager, but it all hinges on staying alive this term.
"If they do that the future could look very bright for Thistle and I'd be delighted if that were the case."
In his time at Firhill, McCall showed a good eye for a bargain, spotting and signing the maverick talent of Erskine and the predatory prowess of Kris Doolan from the junior game and turning them into established Partick first-team players.
McCall is especially excited about the return of Erskine.
The former Firhill gaffer said: "I think Chris can make a massive impact for Thistle down the stretch. He has that ability to do the unexpected and, for me, he is the photo-fit for what makes a great Thistle player. There is no reason he can't go on and become a talisman for the club.
"But Archie has made some very shrewd signings … and I think Lee Mair could turn out to be the shrewdest of the lot.
"Experience is vital at the centre of defence and you can already see the positive impact Lee is having on young Conrad Balatoni.
"Lee has a point to prove after leaving St Mirren having not had as much football as he would have liked. He will be out to show he can still cut it and the early signs are very positive for Thistle.
"Prince Buaben is also a fantastic signing. He will really add a new dimension to their midfield."
So, will Thistle beat the drop?
McCall said: "It is a four-horse race for the relegation play-off slot between Thistle, Ross County, Kilmarnock and St Mirren. But the signings Thistle have made in the window may just have tipped things their way."