The 22-year-old came through the youth system at the Stadium of Light and this season proved to be a core part of the U23 side.
This season he also made three appearances for the senior team in the EFL Trophy.
Despite being with the Black Cats for a number of years now, with his contract expiring this summer, the club made the decision to release him.
This season Sunderland had a successful year in League One and were able to make it to the play-off final where they saw off Wycombe Wanderers 2-0 to gain promotion to the Championship.
Therefore, as Alex Neil’s side prepare for life in the higher division, the standard they are looking for in the youth teams has no doubt improved too.
Whilst the 22-year-old was performing well for the U23s, considering he has had two loan spells to the National League and then Spennymoor in the National League North it seems unlikely that he would be able to make an impact at the Stadium of Light especially as they approach the Championship.
Quiz: Can you name which club Sunderland sold these 23 players to from the last decade?
It’s always a hard decision to release players when they are performing well at their level but realistically, it was looking unlikely that he was going to be getting game time at Sunderland anytime soon.
Furthermore, with the Black Cats now a Championship side again, their focus has to be on staying up and making sure the players they have in their ranks are up that standard.
This move is one that’s probably best for both parties as Richardson can now play regular first team football himself too.