New Zealand will be without Ross Taylor and Tim Southee, who has a "slight hammy niggle", for the first ODI against Sri Lanka in Christchurch, batting coach Craig McMillan has said. The injury is nothing to worry about, he said.

"Ross has gone home to spend a couple of days with the family. He won't be part of this first game. Tim Southee has gone home as well for a couple of days' rest. It's important that we give some of the players a bit of R&R, a little rest before we get into a really hectic season.

"Tim had a slight hammy niggle before that second Test in Wellington. It's just a little bit of time to recover, as much physically as mentally. There have been a couple of long tours thrown in as well and Tim's played pretty much every format. Just a couple of days' R&R and he'll come back when we head north.

"No injury problem [for Taylor]. You'll find most players have got niggles and have tape around certain parts of the body. It's part of being a professional cricketer. There are very few players playing at bang on 100%. No major issues."

New Zealand will play the Sri Lanka series with the same squad that they selected for the World Cup. Fast bowler Kyle Mills, who had to return home from the series against Pakistan in the UAE in December with a groin strain, is part of the World Cup squad, but is not back to full fitness yet. He will not feature in the first ODI, either, McMillan said.

"He's still resting but he's not far off. He's been bowling, I think he's coming off full runs," McMillan said. "So I think he'll join us as we head north and he's looking forward to some game time."

To cover for Southee and Mills' absence, Matt Henry, who missed out on the World Cup 15, has been added to the squad. However, he's being brought in "just in case", McMillan said, with Adam Milne, Mitchell McClenaghan and Trent Boult set to make the playing eleven. "Adam, Mitch, Trent, all three likely to play. Matt Henry is going to come in as cover. Obviously he was very unlucky not to make the [World Cup] squad. He'll come out and join us tomorrow, he's playing for Canterbury today at Rangiora [in the Ford Trophy]."