The financially troubled Ibrox side, and the Lloyds Banking Group, have been eagerly anticipating an estimated 10 million cash injection from competing in the elite club competition to help reduce the club's 31m debt.
However, it has emerged that their path to the group phase may not be automatic if CSKA Moscow or Lyon are the winners of this year's Champions League.
The Russians have already failed to qualify for next season's Champions League and Lyon are also in danger of missing out – unless either one claims the trophy in Madrid on 22 May.
UEFA changed the rules for qualification after Liverpool beat AC Milan to win it in 2005. They had finished fifth in the Premiership that year and should have had to settle for a UEFA Cup place. Now holders qualify automatically – and that could pose problems for Rangers.
"The top 12 countries in Europe have their champions qualify automatically but we're currently 13th," said an SPL spokesman. "As long as the eventual winners have already qualified through their own league then Rangers will be okay. However, the Russian season has recently finished and CSKA Moscow finished fifth, meaning they will miss out.
"Lyon could also fail to claim a place. There are only four points between the top six clubs in Ligue 1. Since only three French clubs enter the competition they may also fail. Should either of those clubs then go on to win the Champions League then Rangers would need to play two qualifying rounds in order to reach the group stage."
However, the consolation for Rangers if that happened is that they would be one of the seeded clubs in that draw.
"Rangers would then be in what is knows as the Champions' Qualifying Pathway," said the spokesman. "That would mean they would have two qualifying rounds to play but both would be against teams from countries ranked below us. They would face ties which would be, on the face of it, much easier than the task Celtic faced last year when they were drawn against Arsenal."
CSKA Moscow are at home against Internazionale in the quarter-final second leg on Tuesday after losing 1-0 in Italy. If they reach the semis they will face Arsenal or Barcelona. Lyon travel to Bordeaux the next evening, 3-1 ahead. Should they qualify, they will meet Manchester United or Bayern Munich.
Speaking in February, Rangers chairman Alastair Johnston said qualifying for the Champions League was "crucial".
From 2011, the SPL champions will only be able to reach the group phase by overcoming seeded clubs from England, Spain, France, Germany and Italy.