"Us and Mount needed a playoff last year to find a finalist and I don't expect any different this weekend," he said.
"It'll come down to which players post the best score and hold their nerve. It should be a great day's golf."
Tauranga topped qualifying in the blue section, almost 10 points clear of Mount Maunganui, while Omanu edged Rotorua to claim top honours in the gold section, although with the playoff courses - Tauranga tomorrow and Taupo next weekend for the final - predetermined at the start of the season, seedings in the pared-back competition didn't matter.
Not that Waretini sees playing at home gives Tauranga any head-start. "Home course advantage has gone for all four teams. Everyone plays this course a lot, just like we play Rotorua, Mount and Omanu a lot, and we proved last year by twice winning away from home that it doesn't matter where you play, you've still got to go out there and play.
"Home advantage is more mental than actual physical on the majority of courses and it's an open playing field when it comes to Tauranga because all 32 guys [in the championship semis] know where to put the ball, their ability is roughly the same and they all know how to score."
Tauranga have enviable depth but Waretini points to Omanu as a team who are solid from No 1 through to 8.
"We're lucky because we had the luxury of leaving out players who'd clearly slot into No 8 in most other teams. But the Rotorua boys will be confident of coming here and bowling us. All the teams have done the work to get here and it's who puts the scores out on the day.
"In our last round against Springfield [won 10-2 by Tauranga] I was the only guy over par in our team. Even though there were some big margins in the singles [only one match went beyond the 16th] the key was guys going under par. Two of our guys were four and five-under par when they won and that's critical."
Traditionally poor in the foursomes format, the defending champions have solidified their combinations this season and reaped the benefits.
Although the playoffs would be decided in the afternoon singles, grabbing any buffer in the alternate shots format was handy, Waretini said.
"Going into the afternoon with a point, or even half a point, advantage gives you a lift. When it's close, as I'm sure it will be, every three or four footer you make is crucial."
Bay of Plenty pennant semifinals:
Championship: Tauranga v Rotorua, Omanu v Mount Maunganui.
Senior A (straight through to final in Taupo): Kawerau v Tauranga
Senior B: Omanu v Lake View, Ohope v Te Teko
Silver Ladies: Omanu v Rotorua, Eastern v Mount Maunganui.
Zonal finals in Whakatane (winners to regional final): Junior: Mount Maunganui v Ohope, Hinehopu v Kaingaroa Forest. Intermediate: Tauranga v Omanu, Springfield v Hinehopu.
