Southee will lead a 15-player squad, which includes five-spin bowling options, for the one-off Test against Afghanistan and two matches against Sri Lanka, which ESPNcricinfo understands will both be staged in Galle, but he is no certainty to feature in them all or the three Tests which follow against India.

Should Southee, who only took six wickets in four home Tests last season, not be part of an XI vice-captain Tom Latham would step up to captain the side.

"Test tours to the subcontinent can ask some really tough questions of pace bowlers due to the nature of the pitches and the heat and humidity," head coach Gary Stead said.

"While we're going over with an open mind around conditions, there is an understanding that all our bowling options may be needed across the different Tests. Tim and I have discussed this, and the need during these overseas tours to balance the workloads of the pace-bowlers, including himself, to ensure the team is best served."

The squad announced on Monday does not cover the India series in October and November, but it's likely a very similar group of players will be involved.

"It's always great when young guys force their way into squads through performance and I know Will and Ben are really looking forward to the challenges of Test cricket in the sub-continent," Stead said.

"Michael's had to show plenty of resilience to rehabilitate his injuries and force his way back into the Blackcaps across all three formats. His all-round skills, and ability to take the ball away from the left-hander make him a great asset, especially on what we expect will be turning wickets in India and Sri Lanka."

Saqlain Mushtaq will rejoin New Zealand as bowling coach for the three away Tests, while former England wicketkeeper James Foster returns as an assistant coach.

The Afghanistan Test, which is not part of the World Test Championship, takes place between September 9-13 and the Sri Lanka matches between September 18-22 and 26-30.

New Zealand play nine Tests from September to December with a home series against England starting in late November. They are currently third in the WTC as they push to reach next June's final at Lord's.

New Zealand Test squad to face Afghanistan and Sri Lanka

Tim Southee (capt), Tom Blundell, Michael Bracewell, Devon Conway, Matt Henry, Tom Latham, Daryl Mitchell, Will O'Rourke, Ajaz Patel, Glenn Phillips, Rachin Ravindra, Mitchell Santner, Ben Sears, Kane Williamson, Will Young