Gallagher, who featured for Claude Puel’s side in pre-season and scored against PEC Zwolle, makes the move to Ewood Park ahead of their game against Wigan Athletic on Saturday.

Last season, Gallagher had a loan spell at MK Dons, before returning to Saints and scoring five goals in 13 appearances for Martin Hunter’s development side.

The 20 year-old, who made 20 appearances for Saints’ first team over the course of the 2013/14 campaign, will now spend the 2016/17 season in the Championship with Owen Coyle’s side.

Everyone at Southampton would like to wish Sam all the best during his time with Blackburn Rovers.