Born in
Bellshill, as a teenager Ritchie had trials with
Manchester United,
Coventry City,
Everton,
Middlesbrough and
Rangers, but chose to join
Celtic in 1971, aged 15. Soon after, Ritchie was 'farmed' out to
Junior side
Kirkintilloch Rob Roy. At Celtic, Ritchie had numerous disagreements with manager
Jock Stein, which led to his transfer to
Morton. He made his debut for Morton on 28 October 1976 and scored 133 goals in 246 games for the club. He was the top scorer in the
Premier Division in 1978–79. Ritchie was famous for what, by the standard of most professional footballers, was a rotund build and apparently blase demeanour. Scottish football journalist
Chick Young saw Ritchie as "the epitome of the Scottish footballer – a fat, lazy bastard, but with great ball skill". Whilst at Morton, Ritchie won a solitary cap for the
Scotland national under-21 football team as an overage player, against
Belgium. He had a falling out with Scotland manager Jock Stein about, as Ritchie felt, having been strung along. He was never selected again. ==Career after Morton==