New Zealand batsman Kane Williamson is under an injury cloud heading into the first of a five-match one-day international series with Sri Lanka.
The two nations will be competing in five 50-over matches in the space of 11 days, which all starts in Christchurch on Boxing Day.
Both sides have the opportunity to move up in the ICC ODI Championship, provided they win the series 4-1 or better.
However, the Black Caps could be without their premier batsman, with Williamson in doubt and possibly set to be rested for the opening ODI.
The newly-crowned world No 1 test batsman, according to the International Cricket Council, injured his right knee while fielding in their second international Test against Sri Lanka in Hamilton.
"We're just working through that knee. It's just a little bit niggly so we want to make sure it's a hundred per cent. If it's not Tom [Latham] is the man we'll bring in as cover," New Zealand batting coach Craig McMillan said.
"We'll see how he feels [on Christmas Day] and make a decision. We need to get it right, if a little bit of a break will help it that's something we'll consider."
Sri Lanka are battling against their own injuries problems, with fast bowler Lasith Malinga ruled out of the entire tour after suffering a knee injury.
The 32-year-old is set to stay in Sri Lanka to receive treatment, with all-rounder Thisara Perera chosen as his replacement.
The majority of the attention in Christchurch will be on Brendon McCullum, with the Black Caps captain announcing he will retire from international cricket after their Test series against Australia which ends in February.
New Zealand had the edge over Sri Lanka in their two international Tests in Dunedin and Hamilton, but the tourists showed plenty of fight despite their losses.
Sri Lanka will be buoyed by the performance of quick Dushmantha Chameera in the second Test, with the 23-year-old claiming 12 wickets to lead the bowling unit.
"He's got raw pace," McMillan said. "Anyone who bowls 145 clicks causes some apprehension at times for batsmen. It's good to see a Sri Lankan fast bowler. Normally they've got guys that aren't quite as quick."