Jackie Blanchflower (Belfast)
116 appearances, 27 goals
Gerry Daly (Dublin)
137 (5) appearances, 32 goals
Roy Keane (Cork)
458 (22) appearances, 51 goals
Sammy McIlroy (Belfast)
390 (28) appearances, 71 goals
Ahead of United's impending trip to Belfast, we continue our look at some of the greatest Irish Reds with a video of some of the finest United midfielders from north and south of the border.
A captain who led by example, Roy Keane was Sir Alex Ferguson's snarling poster-boy for one of the most silver-laden periods of the club's history. Unyieldingly tough in the tackle, the Cork-born middle man hauled the Reds to victory time after time through sheer grit and endeavour.
Another Republic of Ireland export, Gerry Daly, could boast the blood and thunder approach of Keane, but the Dublin schemer had many other strings to his bow - most notably his unerring passing and ice-cool nerve from the penalty spot, from which he scored 16 of 17 spot-kicks for the Reds.
A pair of Belfast boys also made their mark on the Old Trafford midfield, particularly as youngsters. Jackie Blanchflower was an underrated presence in the star-studded Busby Babes, while Sammy McIlroy set the tone for his Reds career with a goalscoring debut against Manchester City, aged just 17.