Shubman Gill is set to miss the first Test against Australia starting on November 22 in Perth after fracturing the thumb of his left hand.
ESPNcricinfo learned the fracture was confirmed on Saturday after Gill attempted a low catch in the slips on the second day of India's simulated training game.
The BCCI has not yet made an official statement on Gill's injury but it is understood that while the fracture is minor, Gill is racing the clock to be fit for the second Test in Adelaide, a day-night fixture that begins on December 6.
Gill's injury means India will have to adapt to fill gaps in their batting order. With captain Rohit Sharma also set to miss the first Test, India have to find an opening partner for Yashasvi Jaiswal, a new No. 3, and also identify their No. 6.
The options for India are KL Rahul and Abhimanyu Easwaran at the top of the order, though Devdutt Padikkal, who was with India A on the shadow tour in Australia, will also remain with the India squad.
Rahul had opened the batting in the second four-day game between India A and Australia A, and also in the simulated training game among the Indian players at the WACA in the lead up to the series opener at the Optus Stadium. After scoring 4 and 10 against Australia A at the MCG, Rahul was struck on his right elbow by a rising delivery from the tall quick Prasidh Krishna on Friday. He did not bat again that day but returned to the nets on Sunday.
Abhimanyu landed in Australia on the back of spectacular form in domestic cricket in India, having scored four centuries in as many red-ball games. But his returns dipped on Australian soil as he fetched scores of 0, 17, 7 and 12 against Australia A. He was out to pace bowling three out of four times - twice edging the ball behind and once to a bouncer - and run-out the fourth time.