Oldham Athletic (youth and early professional years) – Milligan came through Oldham's system and established himself in the late 1980s, contributing to their rise under Joe Royle.
Norwich City (1991–1993) – Signed by Norwich; made appearances in the Premier League and domestic competitions during his time at Carrow Road.
Blackburn Rovers (1993–1995) – Moved to Blackburn, featuring as they became a top-flight side under Kenny Dalglish (though by the time of the 1994–95 title most playing time was shared among squad).
Shan... / later clubs – After spells in the English top divisions he also played for other clubs before retiring; notable later career included time back at Oldham and other lower-league sides.
International career
Qualified for and represented the Republic of Ireland at senior level. Milligan earned caps in the early 1990s and was part of Ireland squads though he did not feature prominently in major tournaments.
Playing style
Energetic central midfielder known for his work-rate, tackling and ability to break up play. Also capable of contributing to forward play and maintaining possession.
Notes
Although born in England, Milligan was eligible for and chose to represent the Republic of Ireland internationally, as were several players of that era.
If you need exact statistics (appearances, goals, caps and dates for Norwich City or international matches), I can fetch season-by-season numbers and cap totals.