Winchester made his first grade debut for Balmain in Round 1 1938 against South Sydney at Leichhardt Oval.
Winchester immediately established himself as a regular in the Balmain side and played in the club's semi final defeat against eventual premiers Canterbury-Bankstown.
In 1940, Winchester made 7 appearances as Balmain failed to defend their premiership finishing 5th on the table.
In 1941, Winchester made 9 appearances as Balmain claimed the minor premiership but were defeated in the preliminary final by eventual premiers St George at the Sydney Cricket Ground.
In his final season at Balmain, Winchester lost his place in the team and missed out on playing in the club's premiership victory over Newtown.