India have retained the Border-Gavaskar Trophy with a 2-0 lead in the four-test series but Rahul's form has been a major concern for Rohit Sharma's team.
With a highest score of 23 in his last 10 test innings, Rahul's place has become untenable as India chase a third successive victory that would seal their place in the final of the World Test Championship in June.
"I have tremendous admiration for the class of Rahul, in fact I call him Rolls Royce Rahul," former India captain Krishnamachari Srikkanth told the Times of India newspaper.
"But it is just not happening for him at the moment. If I was the chairman of selectors, I would have gone up to him and told him to take a break..."
Former test bowler Venkatesh Prasad took to Twitter to criticise the "rigidity of the management to persist with a player who just hasn't looked the part".
Rahul has retained his place for the last two tests against Australia but is no more the team's vice-captain which may be perceived as a sign of his imminent exclusion.
"Of late there has been a lot of talk about his batting, but for us as team management, we always look at the potential of any individual, not just KL," skipper Rohit said in Delhi.
"If the guy has potential, guys will get that extended run. It's not just about KL, but anyone."
Gill's potential is even harder to overlook though.
The 23-year-old already has a century in all three formats and his last seven international knocks include four hundreds.
The elegant right-handed batsman smashed 208 in a one-day international against New Zealand in January and his unbeaten 126 against the same opposition last month is the highest T20 score by an Indian batsman.
"With all due respect to Rahul, it is time to play Shubman," former opener Srikkanth said. "You can't keep a player waiting when he is in the form of his life."
