There are plenty of options as we see; Mayank Aagrwal, C. Pujara, Rahane and even SKY all were opener somewhere on their career. But now they all facing lateral issues with form.
With Rahul out of the series, Gill will probably be considered to open the innings contrary to the reports which came earlier. Gill, who was announced in the squad as a middle-order option, now has to bat at the top because of the little experience he gained in the series against Australia and England. Mayank Agarwal has the strongest case to open alongside Gill. However, the possibility of Rahane or Suryakumar Yadav opening the batting cannot be ruled out as both these batters have opened while playing for Mumbai in the domestic circuit.