Celtic's Charlie Mulgrew has admitted the Old Firm games will take precedence over their Europa League clash with Atletico Madrid.
The Hoops were reinstated into European competition after it was found that Sion had used ineligible players, which subsequently led to them being expelled.
Neil Lennon's side travel to Spain on Wednesday to play Atletico, before facing their arch rivals at Ibrox on Sunday.
At this early point of the campaign Rangers top the SPL and are ahead of second place Celtic by just a solitary point.
Mulgrew insists the Glasgow derby is a fixture that has few equals across Europe and remains the priority.
"Europe was always a bonus this year," he said. "The priority was always going to be the league.
"This is a big game for us and a great experience for all the players but I think Sunday is a bit more important.
"It is a massive week, there are going to be a lot of massive games this season and we all look forward to them all."
Celtic's players had resigned themselves to missing out on facing continental rivals this term, but they are now intent on making the most of their unexpected opportunity.
"Of course it is a bit of a lifeline," he added. "We played quite well in Sion but lost the game 3-1.
"It was fortunate in the way it panned out but we are definitely out to prove a point now and hopefully we can get a result in Madrid.
"We have to be confident, we are playing a good team but we have to believe in ourselves."