Holman signed for Villa on Bosman terms before the dismissal of Alex McLeish.
"I was thinking about Brett recently when Alex McLeish was sacked and I hoped that he wouldn't be affected," Bosnich told the Birmingham Mail.
"I hope he is going to be okay now with the new manager coming in because he's a really talented player.
"He's got the opportunity to show what he is made of and he's most definitely just got to get his head down and impress.
"It will take him a little while to settle in but not too long.
"In my opinion he is a really good addition to the squad."