Barker began his coaching career with Shrewsbury Town working alongside Alan Durban and once Durban left for Stoke City in December 1978 Barker took over as manager of the "Shrews". He remained at Shrewsbury for nine months before taking up the position of assistant manager to John Barnwell at Wolverhampton Wanderers and helped Wolves to lift the League Cup in 1980. In the summer of 1981 Stoke manager Alan Durban left for Sunderland and he recommended Barker for the job and the Stoke board duly went with his advise and appointed Barker. His time at Stoke got off to a great start as Stoke beat Arsenal on the opening day of the 1981–82 season. However it was a tough season for Stoke as they battled against relegation finishing just two place above the drop zone. The 1982–83 season saw Barker bring in some quality players such as George Berry, Mickey Thomas, Sammy McIlroy and Mark Chamberlain as Stoke enjoyed a good season with a number of exciting matches. However in the summer of 1983 Barker decided to change his tactics to be a more direct team using the long ball style of play. It did not go down well with supporters or indeed players and results were not good and Barker was sacked in December 1983.