Mitchell Marsh is set to return at No. 3 for Australia but as a batter only in the first T20I against West Indies as he continues to recover from his ankle injury, while Marcus Stoinis is expected to be fit for Sunday's opening T20I against England, with the pair of allrounders vital to the balance of their World Cup side.
However, Finch did note that Stoinis' absence from this two-game series against West Indies and Marsh's inability to bowl could change the structure of the side in the short term, given they will have fewer bowling options in their top seven, but he was adamant Marsh would play as a specialist batter.
"Hundred percent, yeah," Finch said. "He's made that No. 3 spot his own in T20 cricket and I think the way that he played in the lead-up and then through the World Cup [last year] is so important for the way that we want to play and gives us a lot of flexibility through that middle order.
"I think he had his second bowl yesterday and he felt really good. He pulled up well from it. So that's a really positive sign. I think for the balance of the side, it's better when they're both bowling because you can get caught a little bit short if you go in with five bowlers. But we'll work that out."
Marsh last played on August 28 in an ODI against Zimbabwe. He missed the three-match series against New Zealand and the three T20Is against India and did not bowl at all while recovering in Perth in September.
Finch explained that the decision to leave Stoinis in Perth was a logistical one given the short turnaround time between the two matches against West Indies in Queensland. The second game is at the Gabba on Friday while the first of three matches against England is in Perth on Sunday. The team will have a five-hour flight across the country on Saturday after playing on Friday night.
"He's at a level where we think that he'll be fully fit for that first game against England," Finch said. "We were just conscious of the travel with a quick turnaround…it can be quite a high-risk game for some guys with some soft tissue injuries so he's just still planning and preparing there. He's such an important part of our side and the make-up of it, especially with his bowling."
The Green question is a vexing one for Australia. He is currently not in the 15-player World Cup squad but is with the team in Queensland and available to play on Wednesday. If Stoinis and Marsh are fully fit there is almost no chance he can come into the 15, according to Finch.
"I don't think so," Finch said. "It's just one of those things. He had a really good tour of India. It was good for him to get an opportunity to open the batting so he'll get more opportunities. I think he'll get an opportunity at some point in this series. Obviously his batting is exceptional and he shows a lot with the ball. He keeps improving every time he gets an opportunity but over the next few weeks, he'll get a run no doubt."
It leaves Australia contemplating playing five specialist bowlers at Metricon Stadium on Wednesday. It is something they have barely done since abandoning the strategy ahead of last year's World Cup. But Glenn Maxwell is the only genuine bowling option in the top seven with Marsh unavailable to bowl and Stoinis absent, unless either Green, Daniel Sams or Sean Abbott slot in.
"It's never easy when you're trying to balance up the side, particularly when the allrounders aren't fully fit at the moment," Finch said. "So that gives us an opportunity to keep tinkering with the squad. We feel as though we've got our best XI in the back of our mind, but it's just not everyone's 100% fit at the moment.
"But we've still got a little bit of time for that over the next two and a half weeks. There's five games plus the warm-up game against India. I think it's important that we keep making sure that we're giving ourselves enough options, because if something does happen in the World Cup the last thing you want is to be caught short in playing only one style of team or only one structure of team."
Mitchell Starc is fully fit after resting from the India tour due a minor knee issue. Ashton Agar remains in Perth with Stoinis as he also recovers from a side issue. Kane Richardson is back training with the squad but won't play against West Indies.