The 2005–06 season was the first for both the Central Coast Mariners and the A-League
Compared with its Sydney rival, the Central Coast Mariners had a far more low-key buildup to the inaugural A-League season. The majority of its squad were experienced players from the defunct National Soccer League. They generally exceeded most expectations, having a very successful season, culminating in two solid displays in the preliminary competitions and reaching the grand final in the A-League.
Note: Flags indicate national team as defined under FIFA eligibility rules. Players may hold more than one non-FIFA nationality.
The Mariners competed in Phillips International soccer sevens tournament played in Hong Kong. Their group featured three of the biggest teams in the world, PSV, Manchester United and Celtic. The Mariners caused one of the upsets of the tournament by defeating a somewhat understrength Manchester United 2–1.
The Mariners were runners-up to Sydney FC in the qualifying tournament held to determine Australia's entry in the FIFA Club World Cup, losing in the grand final 1–0.
Group B