The margins have always been fine on the Central Coast and that’s why one player signing became the undoing of Paul Okon’s tenure at the Mariners - the $320,000 failed investment on Spanish striker, Asdrubal.

The thrifty Mariners pegged all their goalscoring hopes on the expensive signing of Asdrubal, brought in to replace Roy O'Donovan after the Irish marksman was ruled out of Okon's plans for the season. While O’Donovan hit the back of the net 11 times with limited service, Asdrubal netted only twice despite being offered greater support. After round 16, he was in the departure lounge of Sydney International Airport headed back to Spain for family reasons.

Expensive lesson: Asdrubal (centre) was the catalyst of Okon's departure and the Mariners quest to rediscover their principles. Credit:AAP

His departure left the Mariners rudderless in attack for the second half of the season, Okon without funds for a Plan B and the team headed back towards the bottom of the table. Now again looking for a leader in uninspiring times, the lessons of Asdrubal will shape the Mariners' immediate future.

Like Okon, the new coach will be given just 90 percent of the salary cap to spend - the minimum allowed. In real terms, that amounts to about $2.6 million. No marquees, no use of salary cap exemptions. Those strict parameters were made clear to Okon during the ill-fated meeting on Tuesday, along with one condition the two parties did not agree upon, understood to be the hiring of a technical director.