Kane Williamson and Trent Boult who grew up together in Tauranga will have vital roles to fill for the Black Caps against Sri Lanka at Mount Maunganui's Bay Oval tomorrow.

Williamson is the team's leading batsman and will captain the team as Brendon McCullum's injured back will see him rested for the upcoming matches against Pakistan and Australia.

Boult has missed the four matches in the series so far with team management wanting him to recover fully from nagging back injuries.

Read more: Bay hosts series showdown


But he is fully fit and can't wait to get stuck into the Sri Lanka batting line-up.

"It is nice to be back with the lads and back at my home ground so it is pretty nice. It is going to be an interesting battle and I am itching to go," Boult said.

"It is a big opportunity for us to press for a convincing series win in my opinion. The guys have been playing really well and I am looking forward to getting out there. There is a pretty healthy battle going on (between bowlers). I think Matt Henry has been superb and Dougy (Bracewell) has been going well all season."

Doug Bracewell, who also grew up in Tauranga, has been left out of the Black Caps for tomorrow's game after a heavy work load in Australia and the test and ODI series against Sri Lanka.

The ODI beginning at 11am tomorrow is the deciding match in the series with the Black Caps holding a 2-1 advantage from matches played in Christchurch and Nelson. It is expected a capacity crowd of 8000 will attend.

On Thursday the two teams meet at Bay Oval in the first Twenty20 international of the series with play beginning at 3pm.