Rangers manager Mark Warburton
At the start of the summer, it seemed that Mark Warburton's men stood an excellent chance of challenging their Old Firm foes in the Scottish Premiership as despite spending the previous year in the division below, they came out on top when the two sides met in the Scottish Cup semi-final at Hampden Park.
Warburton celebrating winning the Scottish Championship trophy last season
And while Sutton agrees that he was worried about his old team while Ronny Deila was at the helm, he has claimed that it is now the Ibrox outfit he is worried for following the work that Brendan Rodgers has done at Parkhead.
"The next few weeks are huge for Rangers. Celtic are getting away from them and they will need to address it before the window shuts or they can forget about making a challenge," he told the Record.
"Deila has gone and in a short space of time Rodgers has turned it around.
Celtic manager Brendan Rodgers
"Four months on from Hampden, the question marks are now hanging over Rangers."
The early signs suggest that Rodgers has managed to change the atmosphere within the Hoops squad. Players like James Forrest and Scott Brown were mostly disappointing last term, but have shown moments which suggest that they could be getting back to their best.
And with the summer signings adding extra quality in areas where they were previously lacking depth, it appears that Rodgers has alleviated many of the concerns that supporters had going into this season.
Meanwhile, although the Light Blues began their league campaign in slightly unsurprising fashion with a 1-1 draw at home to Hamilton, their form in the League Cup has been sensational, especially considering that they have had nine new permanent signings to integrate into the squad.
And with the group-stages of that competition acting as their pre-season - as they only managed to fit in two friendlies around it - it may take slightly longer for those new faces to really get going for their new club.
But Sutton is convinced that regardless of how their current squad gets on, if they do not add more quality before the window shuts, they will struggle to put themselves anywhere near the title picture.