Seb Ryall is ready to step into a key defensive role at the club following the departure of one man in particular.

The 21-year old has his eyes firmly on the central defensive vacancy left by Simon Colosimo who joined new A-League club Melbourne Heart during the off-season.

Ryall, who has overcome some tough times recently having charges against him dropped for engaging in a sex act with a minor, is now ready to put all that behind him and become a major player for the reigning champions.

''It's a good opportunity now that he [Colosimo] is gone and I feel like I've done really well this pre-season,'' Ryall said. ''Stephan (Keller) played as the right-sided central defender last year and that often meant he was closest defender to me, so we've already learnt how to play together.

''I feel most comfortable playing at centre-back and I'd like to have it cemented before we come up for round one. I much prefer it to playing right-back - I don't really like right-back.''

Sydney are in the middle of the Festival of Football and are preparing for tonight's clash with Scottish champions Rangers.