Hughes was sacked after his summer signings failed to fire.
"'The perception is that I brought in a lot of players at one time that disrupted the dressing room, and that was the reason they had a bad season. But the dressing room was damaged when I got there," Hughes told the Mail on Sunday.
"We'd got through the first season and stayed up, but I knew that group couldn't keep us in the Premier League. I tried to add qualities I thought were lacking, brought in good characters. But, in the end, if the mix is tainted you can't do anything."