During a career which lasted from 1964 to 1976, playing for Coventry City, Sheffield Wednesday and Everton, he would make a total of 392 league appearances and score 32 goals.
Despite this lack of success at Wolves, Clements caught the eye of Coventry City manager Jimmy Hill who paid £1,500 for the 18-year-old at the start of the 1964–65 season.
Clements made a fine start to his City career, scoring on his debut on 23 January 1965 against Northampton Town and netting eight times in his first ten matches.
He played as an outside left for much of his time at Coventry for whom he made 228 league appearances (255 including cup games) and scored 30 goals in total over a period of seven seasons.
In total, Clements made 85 league appearances in his time with Everton scoring six goals (he took over as the clubs penalty taker) and became one of the most respected midfielders in the top flight.
However a home defeat to Sweden in October 1975 and a loss in Belgrade to Yugoslavia in the final group qualifier the following month stopped Northern Ireland progressing to the last eight knock out stage.
Clements continued as manager into 1976, however results were disappointing culminating in Northern Ireland losing all three matches in the British Home Championship in May of that year.