American striker Carson Gorecki scored 11 goals in eight matches but has returned to the United States.
He has been a leading player for the club, helping his side score 42 goals while conceding just five.
While Caversham coach Steve Fleming accepts he will be without Gorecki, he was keen to retain the services of talented goalkeeper Liam Little.
Little is unlikely to play, however.
He has been selected in the New Zealand side to go to the Beijing Olympics in China in August and has been instructed to stay off the field this weekend.
The team will play two matches against the Chile under-23 team next week in Wellington as part of its Games build-up.
That decision has annoyed Fleming, who is angry no-one from New Zealand Football has called him to advise him of the situation.
"I think it is quite bizarre that Football New Zealand [NZ Football] now don't deal with the clubs," he said.
"They [NZ side] are not going away until Monday and don't have a game until Friday week and he's not allowed to play.
"Nobody has told us he can't play; they've just told the boy he can't play. So I want to hear it from them."
Fleming was waiting on a call from the national body last night to confirm its stance.
Caversham has been the form team for the past three or four seasons and has made the Chatham Cup semifinals for the past two.
That experience should serve it well, but Tech has been in good touch and won the Cup in 1999.
"I hope the players are aware it is hard work to get to the finals. I hope they sit down and think real hard about it because these opportunities are not there every week."
At stake is a place in the Chatham Cup quarterfinal and, as a bonus, the winning side will win the peacock trophy, presented to the Dunedin team that goes the furthest in the Cup.
Last weekend, Caversham demolished Invercargill-based Spirit FC 12-0, but Tech has also had a good run in the premier league.
Veteran striker Aaron Barnes leads the league with 14 goals from eight matches, including six against the Youth Development side and three against both University and Grants Braes.
Midfielder Andy Coburn has also been in good touch with eight goals.
However, Tech coach Mike Fridge was not expecting a high-scoring game between what he said were two well-matched sides.
"I'd be very surprised if this was a high-scoring game because both teams don't concede a lot of goals," he said.
"We've scored a very similar amount of goals and conceded a similar amount. So there is nothing between us on paper.
"To win this, we are going to need everybody playing at the top of their game. This is by far the biggest game of the season."
The game kicks off at 2pm.
