Hyderabad beat Rajasthan Royals by 36 runs in the last qualifier in Chennai on Friday to secure a place in their third IPL final.
But that win came after a crushing eight-wicket defeat by two-time champions Kolkata in the first play-off in Ahmedabad on Tuesday.
Hyderabad's only title in the world's most lucrative T20 tournament came in 2016 under another Australian, David Warner.
Fast bowler Cummins, for whom Hyderabad paid $2.5 million in the IPL auction, led Australia to both the world Test championship title and an ODI World Cup triumph last year.
"Very practical guy, very humble, very empathetic with his fellow teammates and coaching staff," Hyderabad assistant coach Simon Helmot said of Cummins.
"He is into the statistics, gets the information he needs against a particular opposition in certain conditions. Doesn't waste time in team meetings, our team meeting today went for 35 seconds," he told reporters.
Hyderabad have racked up record IPL totals of 277 and 287 in a high-scoring tournament, with Cummins' astute leadership and rotation of bowlers also an advantage when defending totals.
Standing in Cummins' way will be fellow Australian and Kolkata quick Mitchell Starc, who rattled Hyderabad's top order in the first qualifier.
Left-arm quick Starc became the most expensive player in IPL history when Kolkata paid $2.98 million (£2.3m) for his services, overtaking Cummins in the same auction in December.
Starc justified the outlay when he returned figures of 3-34 at the world's biggest cricket stadium on Tuesday, including bowling fellow Australian and Hyderabad opener Travis Head for a duck.
Kolkata the team to beat
Kolkata, led by India's Shreyas Iyer, have been the side to beat in the competition and topped the 10-team table with 20 points in the league phase.
Apart from the big signing of Starc, Kolkata brought Gautam Gambhir on board as a mentor after the former India batsman led the team to two titles in 2012 and 2014.
Kolkata beat home side Chennai Super Kings to lift their first title the last time they played a final at the M.A. Chidambaram Stadium.
"I'm very confident that KKR are going to win here," Australian cricketer-turned-commentator Matthew Hayden told Star Sports, pointing out that a few days off had given them the opportunity to understand their opponents' strengths and weaknesses.
Kolkata have lost just three matches all season, with all-rounder Sunil Narine promoted to open the innings and leading their batting charge with 482 runs, including a century.
Spinner Varun Chakravarthy and fast bowler Harshit Rana have also shared 37 wickets between them.
However, Kolkata's bowlers will be wary of Hyderabad's left-handed opening pair of Head and Abhishek Sharma, who have given their team many strong starts.
Head has scored 567 runs, with a century and four fifties, to stand fourth in the IPL batting chart led by Royal Challengers Bengaluru's Virat Kohli on 741.
Abhishek has been described as a future India star with his 482 runs and a punishing strike rate of more than 207.