By Jude Summerfield Aston Villa after set to confirm the imminent arrival of Chelsea defender Ian Maatsen after agreeing a £37.5m transfer fee and a six-year contract. The Dutch left-back spent the second half of last season on loan at Borussia Dortmund and helped the Bundesliga giants reach the Champions League final, having been handed few opportunities by former Blues manager Mauricio Pochettino. Dortmund sporting director Sebastian Kehl had previously insisted the club would do their utmost to sign Maatsen alongside fellow loanee Jadon Sancho on permanent deals this summer. However, it soo…