Davie Provan is confident that Celtic can progress to the Champions League Round of 16 in early December.
The Hoops currently sit third on the Group G table, equal on points with Benfica, five behind group leaders Barcelona and four ahead of Spartak Moscow.
Despite the 2-1 loss to Benfica on Tuesday night, former Celtic star Provan is convinced that Neil Lennon's men can get the required victory over Spartak on December 5 as he feels comfortable Barca will get the better of the Portuguese side on the same night.
"They must get a better result at home to Spartak Moscow in a fortnight than Benfica can muster in Barcelona," Provan wrote in his column for SunSport.
"And that's a scenario Lennon would have taken before a ball was kicked.
"It's a gilt-edged opportunity every Celts player must grab when the Russians come to Glasgow on December 5.
"Yes, they got what they deserved in the Stadium of Light. They lost to a technically-gifted Benfica team."
He added: "Spartak's campaign is over, they can't even qualify for the Europa League. So they'll have no incentive when they arrive in Scotland.
"Of course, the same could be said of Barcelona. They've won the group and could take a foot off the pedal at home to Benfica.
"But even if they make six or seven changes, they still have the quality to see off the Portuguese.
"Celtic can complete the job and join Europe's elite in the last 16 in the New Year - even if some of the biggest names (like Manchester City and Chelsea) aren't there with them."