Westhoughton Rangers finished tied at the top of their under-16s league with Boothstown FC after a 22-game season, with a decider set to take place tonight.
Unless the Bolton Bury & District Football League (BBDFL) changes its mind, though, Rangers will be able to field only seven fit players, as several players will be attending compulsory revision classes.
The team’s manager, Mark Hester, said he was “disgusted” at how the league had treated the boys, after their hard work throughout the season.
Westhoughton High School’s headteacher has requested that the school’s players are not involved in the match, with six or seven of the team attending the school.
Chorley-based Southlands High School, where two Rangers players are educated, has also sent the club a letter asking for pupils not to play in the play-off final.
BBDFL’s chairman, Warren Barlow, said Rangers had been offered several dates for the final and their “excuses” were a sad reflection on the club.
Rangers are also competing in a cup final on Sunday, less than 48 hours after the scheduled play-off final.
Mr Hester said: “We feel utterly disgusted at how a charter standard league has treated our children.
“The lads are absolutely distraught. I think it’s a disgrace to us really. They just will not budge on the matter.”
The club argues the players were unable to fulfil a midweek date offered to them because of GCSE exams, with revision classes now preventing them from playing tonight.
Mr Hester added that the league initially told them the play-off match could not take place after the May 18 cup final because of their insurance coverage, but claimed the league backtracked and said it was so their end-of-season awards would not be affected.
Mr Barlow said: “All the play-off matches have been played this week and no other teams have had any issues.
"The main reason they want to postpone it is because they have a cup final on Sunday. Teams are too focused on winning. It is the bane of grassroots football.”
It is understood Boothstown would be able to play the fixture, and therefore win the league by forfeit, if the match is not rescheduled.