Arsenal and Chelsea could be set for an end-of season play-off to decide which team gets an automatic spot in the Champions League group stages next season.
That's because the two teams have a very realistic chance of finishing level on points in the Premier League: if the Gunners win 2-1 at Newcastle and Chelsea draw 0-0 at home to Everton on the final day, the teams would be level on points, goal difference and goals scored.
That would make the clubs joint third and Arsenal and Chelsea would have to face a play-off for the automatic Champions League qualification spot, with the loser having to go into the preliminary rounds in the summer.
Scheduling the match would be a huge headache for the Premier League, since Chelsea have an end-of-season tour to the USA to play friendlies against Manchester City next week, and then there are England friendlies on May 29 against the Republic of Ireland and then in Brazil on June 2.
Neither club would want the season to stretch into June, but the play-off regulation is part of Premier League rules.
They state: "If at the end of the season... the question of qualification for other competitions cannot be determined because two or more clubs are equal on points, goal difference and goals scored, the clubs concerned shall play off one or more deciding league matches on neutral grounds, the format, timing and venue of which shall be determined by the board."
Whether it happens or not, the two London giants won't be the only sides facing an end-of-season play-off.
The same fate awaits lowly Newport County and Mansfield Town, the two sides who won promotion to League Two this season.
The reason? Wigan's failure to avoid relegation, which effectively knocks a team out of the League Cup.
Wigan's victory in the FA Cup final earns them a place in the Europa League next season, and teams playing in Europe are automatically granted byes to the third round of the League Cup.
The same courtesy would be extended to Wigan - despite the fact that they will be playing in the Championship.
That messes up the numbers further down the league, meaning that Mansfield and Newport - who went up as Conference champions and play-off winners respectively - would have to face each other for the right to enter the first round of the Cup.
The same thing happened when Birmingham City were relegated despite winning the League Cup two years ago. That year, Crawley Town beat AFC Wimbledon in a play-off in late July to make the first round.