[3] At the start of the 2005–06 season Alcock was awarded a first team contract along with fellow youth teammates Tom Clarke and Jake Smeeton.

In February 2008 Alcock had to play in goal after an injury to Steve Mildenhall against Walsall; he came on at 0-0 but Yeovil ended up losing 2–0.

However, after an injury he has found himself in a more peripheral role, made harder by the January arrivals of additional full backs Kieron Freeman and John Brayford.

In his second season at United, Alcock again found match time hard to come by, and as a result joined fellow League One side Doncaster Rovers on a 28-day loan on 10 November 2015.

[17] On 1 February 2019, following his release from Cheltenham, Alcock re-signed for Yeovil Town on a contract until the end of the 2018–19 season.