Chennai/UNI: New Zealand's unbeaten start to the ICC Men's Cricket World Cup has been dampened with news that captain Kane Williamson has a fractured thumb and will be unavailable until the backend of the tournament.

Williamson was struck on his left thumb by an errant throw while attempting a quick single against Bangladesh in Chennai on Friday and scans confirmed that the experienced right-hander has picked up an undisplaced fracture.

The latest setback is not related to the knee injury that Williamson has battled in the recent past, but it will still keep the experienced captain on the sidelines in the short-term.

Batter Tom Blundell will travel to India as a cover, should Williamson not recover in time to play again in the tournament. But New Zealand coach Gary Stead was hopeful that the 33-year-old will still have a role to play in their campaign, an ICC report said.

“Firstly, we’re all feeling for Kane to have this occur after all his hard work to return from his knee injury,” Stead said.

“While it’s disappointing news, the initial diagnosis has given us some optimism he can still feature later in the pool play following a period of rest and rehabilitation," he said.

“Kane is clearly a massive part of our side and a world class player and captain - so we’ll look to give him every opportunity we can to return in the tournament,” Stead said.

Blundell will only be available for selection should New Zealand receive approval from tournament organisers for a change in their squad. Stead reposed his faith in Blundell, marking out his recent run in Asia.

“Tom’s been with the one-day side on tours to Pakistan and Bangladesh and performed well,” he said.

“He covers multiple positions in the batting order and his wicket-keeping skills are also an added bonus as a back-up,” Stead added.

New Zealand's next match at the World Cup comes against Afghanistan in Chennai on Wednesday.