Craig Beattie says Rangers' 1-1 draw with Kilmarnock on Saturday means "the season's lost" for Steven Gerrard's team.
Rangers are now ten points behind Celtic in the Scottish Premiership after the Hoops earned a late 1-0 win at Dundee on Sunday.
Beattie, who made 50 appearances for Celtic, says the league title is now out of reach for Rangers, who still have to visit their old rivals at the end of the month.
"For me, it was probably alive going into the weekend; Rangers probably had an outside chance depending on how they were going," said Beattie.
"But I think ten points clear with eight games to go, Celtic having Rangers at Celtic Park, I think Celtic are going to have too much and I think they're going to run out comfortable winners in the end."
Rangers are now four games without a win, with their loss to Kilmarnock coming off the back of a Scottish Cup exit to Aberdeen in midweek, so if they don't win the title it will mean a season without any silverware for Gerrard's side.
"I think the season's lost," said Beattie. "I've been on record and I've been quite critical of Rangers this season so far.
"Semi-finals of the League Cup, quarter-finals of the Scottish Cup - they are now ten behind the league leaders with a massive goal difference, so I think it's gone and I think Steve Gerrard's got a lot of work to put in place for even starting next year.
"The last week for Rangers and Steven Gerrard was a bit of a bombshell. You've gone out the cup and pretty much lost the league within the space of four days so he's got a massive job on his hands just to try and rejuvenate and re-galvanise the squad and get them going for the remainder of this season."