During successful loan spells in 2016 and 2017 with the Robins, Jack made 38 appearances and scored 18 goals before returning to United in January 2018.
The 20-year-old joined us as a scholar at the start of 2014-15 season after leaving Leeds United.
He was offered a contract by United's management staff after impressing for the development and youth sides over the course of his two-year spell as a youth trainee and is now in his second year as a professional with the Iron.
Dyche recently spent a month on loan at Boston United.
