Brock signed professional forms for Oxford United in 1979 and spent eight years at the club, scoring 26 goals from 246 League games. He was with Oxford as they rose through the divisions, enjoyed two years in the First Division with the club, and played in the team who defeated Queens Park Rangers in the 1986 League Cup Final. Brock holds a special place in Everton's supporters' folklore: in a League Cup tie against Everton at the Manor Ground in January 1984, Brock's back pass was intercepted by Adrian Heath, who scored a late equaliser; Everton won the replay, and this is viewed as the moment when their fortunes began to improve.