'Friendly' can often be a misleading term in football. Pre-season games with nothing to play for? Fair enough. Tour matches? Sure. But once you get to the international stage, friendlies are not always full of fraternal goodwill.

Rivalries, you see, tend to run deeper than rules and regulations. Tradition trumps circumstance. So it usually is with games between the home nations: shared history dictates that these are matches that matter more than most – to both fans and players.

Wednesday's game between Scotland and Northern Ireland – Norn Iron to those in the know – promises to be a competitive affair, even if both sides will have one eye on Sunday: Gordon Strachan's side welcome Gibraltar to Hampden Park for a Euro 2016 qualifier, while the Green and White Army host Finland.

The latter assignment looks especially tricky, meaning it would be no great surprise to see Michael O'Neill rest a couple of players in Glasgow. Having made a superb start in their quest to reach France 2016 – wins over Hungary, the Faroe Islands and Greece took Northern Ireland top of Group F after three games before defeat to Romania tempered excitement – they know that their ties against Finland will be crucial for survival. It is unlikely, for instance, that striker Kyle Lafferty will play 90 minutes ahead of such a big game, even if the former Rangers man would love to prove a point.

With an easier fixture on the horizon and home advantage, Scotland are understandable favourites to win on Wednesday. Their home form has also been strong under Strachan: before the 3-1 defeat to England in November, they had seen off the Republic of Ireland and Croatia and held the USA.

Strachan will have been buoyed by Darren Fletcher's return to form and fitness for West Brom, but the midfielder could have to settle for a place on the bench, with James Morrison and Scott Brown having dovetailed well in midfield in recent months. Goals have been fairly hard to come by, however, and it will be interesting to see whether Strachan opts to draft in Jordan Rhodes for his apparent first-choice pairing, Steven Naismith and Steven Fletcher. With Shaun Maloney and Ikechi Anya supplying the bullets, an in-form frontman could make hay in attack.

Most signs, then, point to a home win. But things are rarely so simple in such matches – even friendly ('friendly') ones.