West Ham face Freiburg in the Europa League last 16 on Thursday in search of a third straight quarterfinal.
David Moyes' team are a goal down from the first leg as they seek more European glory after winning the Conference League and reaching the Europa League semi-finals last season.
But the outcome of the match will have repercussions for more than simply West Ham's season.
Tottenham, Aston Villa, Brighton, Wolves, Newcastle, and Chelsea will watch closely.
This is because the result could determine which country gets one of Uefa's new European performance slots and an extra place in Europe.
Since 2003-04, eight groups of four clubs have played each other three times at home and away, with the top two advancing to the knockout phase.
Next year, 36 clubs will compete in a 'Swiss' style, playing eight matches against eight different opponents, four at home and four away.
Top eight clubs advance directly to the final 16, while ninth to 24th place teams play two-leg play-offs to advance.