The 56-year-old said that the atmosphere in Villa's dressing room was low when he arrived and in his eyes it was necessary to sell players in order to start all over again.
Since his arrival at Villa in 2016, Bruce brought has balance to the club by signing experienced players such as John Terry and Glenn Whelan.
"I think that's the biggest challenge I've probably faced in my managerial career. The club getting relegated had a horrible atmosphere to it and all them lads in the club lost half their salary, so as soon as I walked into the club there were a lot of miserable faces for a start", the manager said.
"I've brought in some experience and the young ones are the ones who have particularly impressed me and they're going to be the future and I think the way forward", he added.