The 23-year-old broke a bone in his left thumb while on tour in Bangladesh in October and is still in some doubt for the test starting tomorrow against the West Indies at the University Oval.
But while the right-hander's injury ''is not 100%'', Williamson was upbeat about his prospects of playing in the opening game of the three-match series.
''We're still judging it day by day but it does sort of improve each day,'' he said.
You get the feeling if the decision was left up to Williamson he would definitely be playing. The injury has no impact on his bowling and he has been able to get through some batting sessions. It is fielding which presents the biggest obstacle.
It is not easy to claim a catch when you have got a splint on your thumb, and Williamson conceded he would need some physical support for the injury while fielding.
He is unlikely to take his usual spot in the gully but hopes to stay somewhere close to the action, rather than be banished to the outfield.
If he takes another knock on the thumb there is the risk of causing more serious damage.
''I think that is what we need to discuss because it won't be 100%. But whether it can be managed and in what way, etcetera, all needs to be spoken about.
''If you get a knock on it, it won't be very nice.''
Williamson expected the West Indies would test his resolve with a few bumpers and coach Ottis Gibson confirmed his suspicion.
''We're not going to go out and try and injure or re-injure somebody but we'll try and make it uncomfortable for him early on, for sure,'' Gibson said, adding Tino Best, Shannon Gabriel and Sheldon Cottrell were all capable of bowling 140kmh-plus.
Regardless, it is a risk Williamson seems happy to take.
''You want to be playing, don't you - a test for your country and in your own conditions.
''I've never sort of had an injury where I've been out and missed cricket matches really, so it has been a bit of change. But we've had some good weather at the Mount [Mt Maunganui] and I've enjoyed a few days off. But it did not last long before I was itching to try and pick up a bat again.''
The Black Caps toured the Caribbean last year and lost both tests. Williamson struggled, scoring just 49 runs in four bats. He batted down the order but now looks more assured at No 3 and should flourish in home conditions.
The Black Caps are ranked the eight-best test nation by the ICC but play above their rating at home. They drew the home series with England earlier this year and competed well with world No 1 South Africa last year.
''I guess there has been a bit more continuity in players and positions and the personnel in the team in general. So I think the boys are confident going into it. We have played well in our conditions in recent series, so the guys are looking forward to it,'' Williamson said.
