IRELAND host Scotland in a competitive game today for the first time since 1986.
That Euro 88 qualifier saw some of the biggest names from the biggest clubs in the British club scene go head to head, today will be more akin to a Championship battle and here are the jey battles that could win or lose the day.
Robbie Keane v Russell Martin
Martin O'Neill sprang something of a surprise when he left Keane out of the starting line-up for the reverse fixture in November, the first time he had been dropped by his country in 13 years. Keane has been battling to prove his fitness on the training ground this week but the tragic death of his two first cousins this week leaves Keane with other priorities today and he may not start.
After sitting out last week's friendly against Qatar, Martin will return to the heart of the Scotland defence where he has proved himself to be a rugged and reliable stopper under Gordon Strachan. Norwich's promotion to the top flight will have done his confidence no ha0rm and his organisational skills will be key to this encounter.
James McCarthy v Scott Brown
A big day for McCarthy as he faces his native Scotland for the first time since an U17 Euro qualifier back in 2007. Assured in possession and combative out of it, his ability to pierce the Scottish defence could prove crucial to the home side's hopes.
He will come up against Scotland captain Brown, who has just concluded one of his finest seasons for Celtic. The tireless midfielder has been at his most enthusiastic and his drive and determination sets the tempo for his team-mates and this midfield duel will be one of the key battles of the day.
John O'Shea v Steven Fletcher
O'Shea's vast experience - he is in line to win his 104th cap today - could prove invaluable in one of the Republic's most important games for years. The extent to which he is able to keep Sunderland team-mate Fletcher quiet could go a long way towards giving Ireland a platform from which to attempt to win the game.
Fletcher goes into this crucial encounter on the back of his first hat-trick in dark blue, against Gibraltar at Hampden in March. The Black Cats striker is not prolific but brings more than goals to the national team, with his hold-up play integral to the Scots breaking quickly and also alleviating pressure on the defence.