New Zealand have picked as many as four spinners in their 15-man squad for the upcoming two-Test series in Sri Lanka, which will also see the start of their ICC Test Championship campaign.

Left-arm orthodox Ajaz Patel and off-spinner Will Somerville have been recalled into the squad and will join Mitchell Santner and Todd Astle in a Test squad well-equipped for spin-friendly conditions in the island nation.

Patel and Somerville had played a decisive role in New Zealand's 2-1 Test series win over Pakistan in UAE last year. While Patel had picked 13 wickets in the series, Somerville had also come out with a match-winning performance, snaring seven in the final Test in Abu Dhabi.

New Zealand coach Gary Stead said the composition of the squad followed a "horses for courses" type strategy and took into account the recent history of touring teams visiting Sri Lanka -- particularly England and South Africa.

“Playing three spinners is an option in Sri Lankan conditions and we believe this group provides the best variations and skill mix on offer,” Stead said.

“England were playing three spinners against Sri Lanka on their successful visit there last year and the slow bowlers also dominated the previous series against South Africa,” he added.

The concentration of spin bowling reserves leaves Trent Boult, Tim Southee, Neil Wagner and Colin de Grandhomme as the pace bowling options. Tom Blundell will act as wicket-keeping and batting cover.

The first Test of the series will be played in Galle, starting on August 14 and the second will take place at Colombo PSS, commencing on August 22.

Squad:

Kane Williamson (c), Todd Astle, Tom Blundell, Trent Boult, Colin de Grandhomme, Tom Latham, Henry Nicholls, Ajaz Patel, Jeet Raval, Will Somerville, Mitchell Santner, Tim Southee, Ross Taylor, Neil Wagner, BJ Watling