The 31-year-old has been heavily linked with English Super League club Salford Red Devils, and UK media reports suggest a deal has already been done.
With 226 NRL games under his belt, Vatuvei is a crowd favourite at Mount Smart Stadium.
Injury limited the bustling back to just 15 NRL appearances in 2016, and persistent knee and hamstring issues have kept him off the field for most of this year.
He has played just once in 2017, in a 24-12 loss to the Bulldogs in Dunedin.
Despite having a contract that runs through to 2019, Vatuvei is said to be weighing up his options.
"I've been made aware - I know that Manu's been looking at his options for a little while but certainly haven't known any of the details, and don't know that any deal is done," Warriors assistant coach Andrew McFadden said.
"But what I do know is that Manu really deserves to finish strong - if that's here or overseas, I'm not sure.
"I hope he gets to get back on the park soon."
Salford, who have ex-NRL star Todd Carney on their books, currently sit in second on the Super League table.
Vatuvei's departure, if confirmed, would follow the arrival of Parramatta Eels back Bureta Faraimo on a short-term, injury-cover contract.
