Coach Eric Black leaves Rotherham United for Aston Villa
Black has left the club by mutual agreement and is expected to become assistant manager to Aston Villa boss Remi Garde.
The 52-year-old former Scotland international striker began his career under Sir Alex Ferguson at Aberdeen.
He is fluent in French after then spending five seasons playing for Metz.
Black managed both Motherwell and Coventry City, before becoming number two to Steve Bruce at Birmingham City.
"He has had an opportunity that he felt he couldn't turn down," said Redfearn. "Eric really bought into what I wanted to do here and was very popular with the players and staff.. Black will join Premier League bottom club Villa at a time when there is suddenly a bit of hope, after going five games unbeaten in league and cup.
Although Villa were taken to two games by Wycombe Wanderers in the FA Cup, to set up this Saturday's home fourth round tie with Manchester City, Garde's men have also beaten Crystal Palace, held leaders Leicester and picked up Saturday's away derby draw with West Brom.
"The way we play I'm pleased with," Garde told BBC WM. "Much better than a few weeks ago. I know I can rely on these players. But when you do not score a goal, you do not deserve to win. We have difficulty scoring goals. Rudy Gestede's injury was a hamstring. I don't know yet how bad.
"I know the fans are not happy but they saw a Villa team fight, with great spirit and, if we keep playing with this spirit until the end of the season, anything is still possible."