After a decorated career of almost 300 matches in the National Soccer League, Greek Superleague and the A-League, Valkanis moved into coaching after ending his playing career with Adelaide United, taking up a position in the club’s youth development program.

In 2013, Valkanis was appointed the caretaker manager of the Reds at the midway point of the season where he led the side to a fourth finish.

Valkanis resumed his role as assistant and National Youth League Head Coach under Josep Gombau and Gillermo Amor where United won the 2015/16 Championship as well as qualifying for the 2015/16 National Youth League Grand Final, going down to Sydney FC in the final.

In June 2016, Valkanis was appointed the Senior Assistant Coach of Melbourne City’s A-League side alongside Assistant Joe Montemurro and Head Coach John van’t Schip before being named the interim manager of the side in January 2017 after the departure of van’t Schip.