If Southampton are to be promoted, they will need to upgrade on a number of their current squad. The good news for Russell Martin is that, should he steer Southampton to an instant return to the Premier League, this will secure the signing of Taylor Harwood-Bellis due to his loan deal including a £20 million obligation to buy contingent on promotion. It would also greatly improve the club’s chances of signing Flynn Downes permanently, with the holding midfielder a real standout performer this season on loan from West Ham United. With Harwood-Bellis just 22 and performing so well alongside Pola…