The club signed the Czech Republic international on the final day of the transfer window.
The manager told the club's website: "I think the two of them could play with each other no problem. They'll be a handful. I just felt that we needed another type like that, an experienced one. I need everybody, the 25 man squad, to perform.
"It is about keeping everyone on their toes. You have got to have people that push each other to do well. As soon as you stop looking over your shoulder as a footballer you become complacent.
"You have got to keep playing with that little bit of fear that somebody might just come in and take your place."
Aston Villa play Newcastle United this afternoon.