Wellington - All Black coach Steve Hansen is sweating on the fitness of lock Brodie Retallick ahead of next weekend's first Test against France in Auckland.
The Chiefs second rower went off injured during Saturday's loss to Crusaders and Hansen confirmed he had hurt his pectoral muscle.
He said it was too early to know how long Retallick will be sidelined.
"It is a worry because that injury short term is probably a couple of weeks (out), long term he could be out for the whole season," Hansen told Radio Sport on Sunday.
"Until we get some imagery and get him in front of our medical crew we won't have too much of an idea."
Retallick's absence would be a huge blow for the All Blacks, with the 27-year-old currently displaying the form that saw him named World Rugby Player of the Year in 2014.
New Zealand's series against France begins in Auckland on June 9, the second Test is in Wellington a week later with the third and final encounter in Dunedin on June 23.