Finch suffered a hip and glute injury while fielding in his side's series-opening loss at Manuka Oval on Friday.

The skipper still top-scored with 35 in Australia's unsuccessful pursuit of a target of 162, but appeared in some discomfort and at one stage required attention from medical staff.

Lyon's belated T20 call-up comes after Cameron Green was released, allowing the 21-year-old allrounder to enhance his bid for a Test debut by playing the red-ball tour game that begins on Sunday.

Australia and India travelled on Saturday to Sydney, where Finch will be assessed on Sunday prior to the T20 at the SCG.

"It progressively got worse during the game," Finch said.

If Finch is out, selectors have a major decision to make regarding his replacement as captain.

Matthew Wade, who served as Finch's deputy on Friday night, is likely to get the nod but Steve Smith is the only other man in Australia's squad to have captained the country in any format.

Star batter Smith has recent experience in T20 cricket, having captained Rajasthan throughout the IPL.

Smith is eligible to return to the captaincy but has not been given any formal leadership position by Cricket Australia (CA) since serving a year-long playing ban and 24-month leadership ban in the wake of the ball-tampering saga.

CA hierarchy, coach Justin Langer and chairman of selectors Trevor Hohns have largely dismissed questions about Smith's leadership prospects over the past two years as being hypothetical.

But fans may soon get a clear idea of where Smith sits, especially given regular vice-captain Pat Cummins is being rested for the T20 series.

Former vice-captain Alex Carey is a contender to replace Finch at the top of the order and could also be asked to lead.

Josh Hazlewood is another former vice-captain in the squad, while Glenn Maxwell and Moises Henriques captain their respective BBL sides.

Meanwhile, India will be without Ravindra Jadeja for the remainder of the T20 series after the Board of Control for Cricket in India (BCCI) confirmed the spinning allrounder had sustained a concussion.

"Jadeja remains under observation and will be taken for further scans if required based on the assessment on Saturday morning. He will not take any further part in the ongoing T20I series," the BCCI wrote in a statement.

Jadeja's concussion and the ensuing substitution of legspinner Yuzvendra Chahal into the fray during Friday's T20 was the source of much angst among the Australian camp, with Langer spotted having a heated discussion with match referee and former teammate David Boon.

Jadeja stayed on the field for the remaining four balls of India's innings after his helmet blow before he was subbed out of the game, with Langer presumably questioning whether Chahal was a true like-for-like replacement.

Chahal went on to claim 3-25 and man-of-the-match honours.

Australian Associated Press