Barnes spent 1982–83 in La Liga with Real Betis, before returning to Elland Road for a run of 27 games and four goals in 1983–84. He was sold by Eddie Gray to Don Mackay's Coventry City for £50,000, and scored two goals in eighteen First Division games in 1984–85. Ron Atkinson subsequently signed him for Manchester United, where he was effectively an understudy to Danish winger Jesper Olsen. An unused substitute in the 1985 FA Charity Shield, he fell out of the first team picture in mid-November of the 1985–86 season, only returning to the starting eleven in October and November of the following campaign. His time at Old Trafford was limited after Atkinson was replaced as manager by Alex Ferguson. Barnes took to hiding in the communal bath waters in the dressing room to avoid Ferguson's famed 'hair-dryer' treatment.