An academy player with Manchester United from the age of 14, Dean sampled his first taste of senior football on loan at Conference North side Stockport County during the 2015/16 season, having turned pro at Old Trafford.
He moved up to League Two side Grimsby Town on loan the following campaign before a full season at Shrewsbury Town in League One, where he twice helped the side to Wembley, in the EFL Trophy and Play-Off finals.
Named in the League One Team of the Year, he was sent out on loan to Championship side Sheffield United ahead of the 2018/19 season. A key performer as the Blades won promotion to the Premier League, he was named the club’s Young Player of the Year and won the Championship Golden Glove award.
In July 2019 he signed a new contract with Manchester United before returning to Bramall Lane on loan. His impressive form has continued in the top flight and in October 2019 he was called up to the full England squad for the first time, having previously represented the Three Lions at U16 to U21 levels.