Danny Ings
It appeared that Saints were not going to sign anyone on deadline day in August 2018 but a late development saw them complete a last-minute deal for Ings.
He signed on an initial loan deal and struggled with injuries in his first season. However, he thrived once his move was made permanent for £20m.
In all, he made exactly 100 appearances for Saints and netted 46 goals, including a stunning 25-goal haul in 2019/20.
He was a hit with supporters given that he supported Saints himself as a boy but a contract dispute saw him sold to Aston Villa this summer for a fee that could rise to £30m.