"I wouldn't say we are done yet,'' he said. "Very rarely, in my experience, is recruitment over until we start playing the first game of the new season.''
It would help explain why there has been no movement on Jerome Ropati. The veteran centre is keen to play for at least another season and coach Matt Elliott has talked about his desire to retain Ropati but the club will need some wriggle room in the salary cap if they want to add to their roster.
They would be able to free up some room in the cap if they could offload prop Russell Packer or fullback Kevin Locke. The Warriors are never short of quality front-rowers and Locke will struggle to find a spot in the starting side with the arrival of Tomkins and half Chad Townsend.
Locke, who could be a bench utility who covers dummy half and most positions across the backline, can be a matchwinner but he's far too inconsistent and the difference between his best and worst performances are too great.
The prospect of Packer leaving seems more realistic. He's an experienced prop - he's played 110 NRL games as well as two tests for the Kiwis - who is still only 23. But he also missed a lot of action in 2013 with injury (he played only nine games) and caused unwanted attention for the club when he urinated on Suncorp Stadium immediately before the Warriors' impressive 56-18 defeat of the Broncos.
Outside backs looms as one area the Warriors could strengthen. Konrad Hurrell can be a slow starter and was dropped down to the Vulcans this season and Dane Nielsen provides little attacking thrust.
On top of that, the Warriors were sometimes short on the wing with Glen Fisiiahi (a fullback), Ngani Laumape (a centre) and Ropati (a centre) often employed there.
The Warriors have placed a lot of faith in Tomkins and there will be considerable pressure on him to deliver. He's clearly a talented player with a terrific try-scoring record (144 in 150 games for Wigan) but the NRL is far stronger than the Super League.
"It has not been easy with all the rumours but I have been completely open about it. It was only signed 10 days ago,'' Tomkins told reporters in the UK. "I am glad it is all over now. It is a change I am ready for.''
Warriors fans will hope it's also something that brings about a change in the club's fortunes.