He began his career with Irish Intermediate League side Crusaders as a half back before joining Cardiff City in 1925 where he converted to defence.
He later returned to play for Crusaders before managing amateur side Whiteabbey, where he won the Irish Football Alliance in his first season.
[3] Watson began his football career as a youth player with Glenarm before joining Irish Intermediate League side Crusaders.
[4][5] Crusaders had previously sold Jimmy Nelson, a childhood friend of Watson,[6] to Cardiff City in 1921 where the Scotsman had impressed.
[9] During his time with Crusaders, he had played as a half back but on arrival at Cardiff, the club's coaching staff believed he would be more suited to a defensive role.
[13] He missed only three further games during the remainder of the campaign for Cardiff, making a total of 33 appearances in all competitions during the year as he formed a defensive partnership with Nelson.
[9][14] In his second season with Cardiff, Watson made a further 45 appearances in all competitions, including playing in all seven matches of their successful FA Cup run.
However, from late December, his season was blighted by injuries; he made only two appearances in the second half of the campaign, the second in a heavy 7–1 defeat against Derby County on 31 March 1928.
The Belfast News Letter reported that the incident had likely turned the game in Linfield's favour, writing "Had that accident not happened, Ballymena would, in all probability, have got the winning goal.
[24] Watson represented Ireland at youth level before receiving his first call-up to the senior side in February 1926, following a number of withdrawals due to injury, for a match against Scotland.