"It has to be a collective. You can't expect good players to come in and make your team great all of a sudden. It takes a while for players to get used to playing among new guys and you learn that along the way.
"We won't see Kieran until at least round three so we still have a job to do with the group that we have got."
There is no doubt that when Foran does eventually take the field, he should be a vital ingredient towards any Warriors revival. He brings a winner's mentality from many successful years at Manly, will provide vital direction and organisation, and could bring out the best in halves partner Shaun Johnson.
But Mannering is adamant the team can thrive in 2017, with or without Foran.
"If Kieran wasn't going to be registered we were still confident in the group we have got.
"It's great to have him but there is not going to be a magic fix. It's more about what we have done over the pre-season and about us putting it out there on the field."
Mannering has taken on the role of vice-captain, as the key lieutenant to Roger Tuivasa-Sheck.
He unofficially had the same position last year - covering for Ryan Hoffman once when he was injured - but has no desire to wear the armband again.
"I definitely had no ambitions to go back into the captaincy role," said Mannering.
"I did a number of years there. I wanted to do what was best for the team. I want to support Roger as best I can and Mooks [Stephen Kearney] thought that would be in a vice-captain role. It doesn't change anything else for me."
Mannering will take the field for the first time this year against the Titans in Palmerston North today, and says he is refreshed and ready to go ahead in his 13th NRL season. The injury-enforced absence from the Kiwis' Four Nations campaign meant an unusually long time at home, with the first family holiday with his young children (Zeke, 3 and Jack, 1).
"We travelled around Kaikoura, Hamner, Nelson and Christchurch," said Mannering. "They were all places that my partner and I went to as kids. [But] this was a different experience, more screaming at the kids and chasing them round than anything else."
He reports that his knee is "all good", although conceding recovery and rehabilitation took longer than expected.
Another huge year looms for Mannering in 2017 - the 30-year-old made 1040 tackles last year, the second highest across the NRL - although a lesser defensive workload would be welcome, as it would indicate signs of progress at the club.