New Zealand batsman Kane Williamson has been ruled out of the ongoing ODI series in Bangladesh and the upcoming tour of Sri Lanka because of a fractured thumb. Williamson will return to New Zealand today and Luke Ronchi will join the squad as a replacement for the remaining Bangladesh ODIs.

The injury, which will require up to six weeks recovery time, makes him doubtful for the opening Test against West Indies, in Dunedin, which begins on December 3.

In the absence of Brendon McCullum and Ross Taylor, Williamson was supposed to lead New Zealand in the three ODIs and two Twenty20s in Sri Lanka. New Zealand's selectors are yet to announce the replacement captain and player for that tour.

Williamson was struck on the thumb while fielding at point in the 35th over of Bangladesh's innings in the first ODI in Mirpur and immediately left the field. His left thumb was dislocated and an x-ray confirmed a small fracture.

"This kind of injury unfortunately means Kane cannot take part in the rest of the tour and he will return to New Zealand to begin his rehabilitation," New Zealand physiotherapist Paul Close said. "Kane is about six weeks away from playing again at this stage."