Mills

Born in Peterborough, Zak came through the Boston United youth ranks before making his professional debut in 2010 for Histon Town. Where he made over 100 appearances across four years before a switch to Boston United in 2014, joining his boyhood club in his first of two spells for the Lincolnshire club.

After two years at Boston, Zak signed for League 2 side Grimsby Town, where he went on to make over 60 appearances for The Mariners across two seasons. Following his departure from Grimsby, Zak enjoyed a successful spell in the Football League, representing Morecambe, Port Vale, Oldham Athletic and Walsall. At the end of the 2018/19 Season, Zak was named as Morecambe FC's Player of the Year.

In 2022, Zak returned to Boston United, where over four years, he made another 100 appearances for the Pilgrims, taking his overall tally to beyond 200 appearances. Zak was named Boston United's Player of the Year at the end of the 2024/25 season and served as their club captain last campaign.

Zak joined the club in June 2026.