"It's a very different challenge, I think, playing him in a test," Williamson said. "In saying that, it will be interesting to see how they produce the wickets, but hopefully the tests bring him down to a more level playing field ...
"When we looked to attack, he certainly picked up wickets so I think the slightly more defensive or slower version of test cricket will make him less effective because he's not a huge spinner of the ball both ways - but he does get it to go both ways."
The Trinidad-born tweaker played alongside Brendon McCullum for the Kolkata Knight Riders in this year's IPL and Williamson said they were working hard on trying to read the finger-spinner's deliveries.
The New Zealand side to play the tests should have a different look, with Kruger van Wyk, Chris Martin, Daniel Vettori and Neil Wagner joining the squad as Jacob Oram, Tom Latham, Rob Nicol and Andrew Ellis drop out.
Wicketkeeper-batsman BJ Watling remains under an injury cloud with a quad strain but is expected to be available for the first test.
- APNZ