With the recent signing of hooker Wayde Egan from Penrith, O'Sullivan has narrowed his priorities over the next year.
"Priority wise the hooker was number one, the big edge back rower number two and probably a centre back rower would have been the third option which I really wanted to do. Next priority would be a big middle."
The Auckland club will juggle three hookers next season. It's far from ideal in terms of salary cap space, but an unfortunate reality with the questions over Nathaniel Roache's future, given his awful injury run, while Karl Lawton is coming back from another shoulder reconstruction.
It's meant the club have one spot left in their 2020 squad, unless there is a surprise departure, and O'Sullivan wants to land the jackpot.
"We need to be patient and wait for the right one," said O'Sullivan, who indicated there aren't really any off contract options. "It will be someone squeezed out somewhere. That's what happens, someone moves that triggers three or four moves someone else. But you can't chase those people because it is against the rules."
O'Sullivan has great hopes for some of young middle forwards coming through at the club and says he is content with the current backline resources.
But 2020 will be a pivotal year for everyone associated with the Auckland club, including O'Sullivan who arrived with a big reputation for talent spotting. There's likely to be plenty of movement at the end of next year, with multiple Warriors off contract, so his abilities will be under the microscope, though O'Sullivan is adamant he's not feeling the pressure.
"Not at all," said O'Sullivan. "We will have a better squad in 2021 than 2020, and 2022 than 2021. So there is no pressure. I know where we are heading. Mark [Robinson), Cameron [George], the coaches know where we have heading. And we've got plenty of talent. We are not worrying about what we haven't got, we are working with what we have got."