A potential Europa League rule change lies in wait should Rangers and Celtic reach the group stages.
However it's one both Glasgow clubs will be well used to by now.
UEFA could be set to allow clubs to make five substitutes in each match once we arrive at the competition proper.
Currently, in the qualifying stages, clubs are only able to make three changes per match.
In a number of European leagues, including the Scottish Premiership, the five sub rule is already in place.
UEFA executive committee member Andrea Agnelli is in favour of the change, saying: "I think we want to make sure that we see this also at international level, in the Champions League, Europa League, so that we have a consistent, harmonised style of play.
"This was a consensus we had across the general assembly when we discussed it amongst ourselves, especially given the congested calendar.
"From October to Christmas, national team players play every three days for three months."
Rangers face Willem II in the Netherlands tomorrow for a chance to face either Galatasaray or Hajduk Split.
Celtic play Riga in Latvia and will face Sarajevo or Budocnost Podgorica should they win.
Aberdeen and Motherwell are also in contention to reach the group stages this season. The Dons face Sporting this week before a potential match against either LASK or Dunajska Streda. Motherwell face Hapoel Beer Sheva for a chance at a play off against either Viktoria Plzen or SønderjyskE.
