Kirkham, Lancashire born wing half Edward Threlfall began his football career with hometown club Kirkham in 1899 before joining Second Division Blackpool, for whom he made his Football League debut at New Brighton Tower in September 1900. Immediately establishing himself as a mainstay of their first eleven, he also became possibly the first Blackpool player to be sent off in a League game. During the fixture against Burslem Port Vale on 15th December, Threlfall was given his marching orders for “rough play” when “a regrettable incident occurred about three minutes off time”. Threlfall later complained that he had not been cautioned “before the referee took this extreme course”.
In 1901-02, Threlfall missed only two of Blackpool’s 34 League games and he also scored his first goal for the club, in a 1-1 draw at home to Glossop North End on 1st February. Threlfall missed only one match of Blackpool’s 1905-06 League campaign, scoring one goal in the proces in a 3-0 home win against Clapton Orient on 27th April, in the final League game of the season. He also scored once in the FA Cup to take Blackpool to a second first-round replay against Crystal Palace, which they won 1-0 at Villa Park. They went on to the third round, their best FA Cup showing while Threlfall was at the club, being eventually knocked out by Newcastle United, who went all the way to the Final.
In all he played 11 seasons for Blackpool, all of which involved finishes in the lower half of the Second Division except his final season, 1910-11, when they finished 7th. Over that time he scored 13 goals in 341 appearances for The Seasiders.