Known for his passing and ball control, he kept his place in the Arsenal side until the signing of Don Howe at the end of 1963-64. Relegated to the reserves, Magill only made one more first-team appearance for Arsenal over the next fifteen months, mainly playing for the reserve team instead. He eventually joined Brighton & Hove Albion in October 1965. In total he played 131 matches for Arsenal, never scoring a goal. At Brighton, he spent three seasons before returning to Northern Ireland in 1968. After retiring from playing Magill coached in Denmark, first as coach at Viborg FF and B109 and then as manager of Næstved BK and Frederikshavn.