Wellens' first role in management came when he joined Oldham Athletic as first team manager from September 2017 to June 2018 when Wellens was sacked following the club's relegation to League Two. Wellens then took over the vacant managerial position at Swindon Town in the summer of 2018 where he led the club to win the 19–20 League Two title on PPG during the COVID-19 pandemic. In May 2021 Wellens’ became manager of the Doncaster Rovers.