It is understood that there is no definitive date of return earmarked for Iyer, who will continue to be supervised by the BCCI's medical staff at the National Cricket Academy in Bengaluru through the near future. Knight Riders, though, have not given up hope, and expect their captain to be back before the halfway stage of the IPL.

Iyer's issues, it is learned, concern a bulge in one of the discs in his spine, which has resulted in an impinged nerve. The nerve runs along the right leg and has caused shooting pain in Iyer's calf, which is compounded by mobility issues. It is understood that Iyer has been given six injections in the recent past to help numb the pain in his back.

He returned to play the second and third Tests of the Australia series. However, the back pain re-emerged during the final Test in Ahmedabad, where having fielded for the first two days, Iyer did not turn out to bat in India's only innings in the match.

After returning home, Iyer consulted a spine surgeon in Mumbai. He was presented with two options: rest, rehab and wait for the pain to subside before resuming strength and conditioning and mobility exercises. If that doesn't work, then move to the second option: surgery. It is understood that the BCCI medical staff even consulted a London-based specialist, who had carried out Hardik Pandya's back surgery, for a second opinion. The London expert, too, advised to stick the first option.

Iyer has told the BCCI medical staff that he wants to explore options before taking the final call on surgery. He has also received full support from the Knight Riders management who helped him consult an Ayurveda specialist for a non-intrusive alternative medicine.

Who can be KKR's interim captain?

Rana has led Delhi in 12 T20s in the Syed Mushtaq Ali Trophy, with eight wins and four defeats.