"By all accounts it will be similar to what we're used to. The green grass might offer a little bit to the seamers initially.
"We haven't selected an XI just yet. We want to have another look tomorrow. The wicket in the past has been liable to change quite quickly."
New Zealand have not lost any of their seven tests since the venue's debut in 2008. They have won three and drawn four, including a stalemate against South Africa in 2012.
Williamson was asked what Patel might deliver.
"He's been bowling well and is an aggressive spinning option. The Dunedin surface has taken a bit of turn and slows up, he's an option we're considering."
The skipper also weighed up the Neesham versus de Grandhomme conundrum.
"Colin can exploit seam movement well in surfaces and Jimmy can bowl with some good pace and make things happen with it. They've got a number of similarities with the bat and in the field."
After losing five straight tosses in the one-day internationals, Williamson was reluctant to venture an opinion on what he might do if the coin landed in his favour.
"I don't want to get ahead of myself with silly ideas like that," he quipped.
"We'll have another look at the surface tomorrow before we make any outrageous comments about what we might do."
Du Plessis was affirmative on Morkel's recall.
"Every time he's bowled in the nets [over the last six months] he's been at his best when I've faced him. All the reports say his back is 100 per cent fine and he's bowled a lot of overs.
"Morne is successful against lefties and that's one of the main reasons he got the nod ahead of Duanne [with New Zealand expected to have four in their top seven].
"Bounce is a huge factor and the angle of the ball as it comes out of his hand - it goes either into right-handers and away from left-handers. He's terrible to face in the nets as a right-hander because you always feel like it's going to hit you in the ribs."