According to Clarke he had a brief phone call with Petrie back in 2010 but it went no further than that:
https://www.scotsman.com/sport/steve...hoice-1-826973
I'd have been very surprised if we'd managed to appoint him back then to be honest. His next post was assistant at Liverpool before going on to manage West Brom, Reading and Villa. Pretty sure family connections helped Killie to land him (think his family are Killie fans) but it's proved to be a brilliant appointment. He's got massive experience with many clubs down south and will likely move on to bigger things again.