The Austrian penned a new deal with Villa this week.
"He scored that last minute goal against Fulham, so I knew bits about him," said the Villa chief.
"But you are never quite sure until you come in yourself to see if he can actually do it.
"The big thing that strikes me is his work ethic. That's the big thing. You don't need to be the greatest player on the planet but if you have got a work ethic it can take you far in the game, if you've got that drive and hunger to succeed."