Rahane, 35, returned to the Indian Test team this year after a great IPL season and a strong performance in the World Test Championship final against Australia earlier this year.
However, he has flopped twice with the bat, raising concerns about his consistency once more.
“Rahane will have to show consistency in his game, which has been his problem even though he has played 80-90 Tests (84). Consistency has been an issue, he will have to overcome it because India have a good captaincy option in him after Rohit Sharma is done.
“Rahane will have to make runs, and then everything else will follow,” Jaffer told media during an interaction organised by Jio Cinema on Friday.
Jaffer said the Indian selectors see a strong captaincy option in Rahane.
“If his form was great from that Australia series after that 36 all-out, the way he led, scored a hundred in Melbourne… had his form remained the same, he would have been the next Test captain. But he lost his form and got dropped,” he said.
“However, he reinvented himself in the IPL and got a chance in the WTC final. He was appointed the vice-captain as well, because the Indian selectors see a good leader in him. He still has age on his side but he needs to score runs, if he does not then he will find it difficult,” he added.
Cheteshwar Pujara’s return to the Test team will also be challenging, according to Jaffer, because the new WTC cycle of 2023-25 will focus on younger players.
“As far as Pujara is concerned, I feel it will be a little difficult going forward,” the former India opener said.
“You also have to start looking at the new boys for the next World Test Championship cycle. Shreyas Iyer and Rishabh Pant will come back. Yashasvi Jaiswal has been successful. (Shubman) Gill will play in all three formats. I feel it will be difficult for Pujara to make a comeback.”
Jaffer, who played 31 Tests and two ODIs for India and holds multiple domestic records, believes Gill will need to learn the craft of batting at No 3, particularly on slow and low wickets.
“Looking at the bigger picture, he wants to bat there for a longer period. But the start has not been the way he wanted.
“In this Test match and in this innings, he had a good chance, the wicket was good, (the team) had got a good start. I felt he played a little loose and he obviously will be disappointed with that dismissal, and that is where he needs to tighten up. He likes the ball coming on to the bat, because of so much of white-ball cricket he is used to hitting on the rise,” he said.
“He wants that pace which is found in white-ball cricket. But in red-ball cricket, on wickets like these, probably in India when he plays, it is not easy to play on the rise. He just needs to understand that and improve his game for those conditions.”
Jaffer stated that Jaiswal has had a fantastic start to Test cricket, which many players can only dream of.
“It has been a dream start, there is no doubt about it. Anyone getting 170 (171) in his debut innings and following it up with a fifty (54) is a dream start that anyone would wish to have. He is on the right track, I have known him from 2013-14 since he used to work with Jwala Singh (coach) and I was also involved,” he said.
When asked about India’s T20 squad for the West Indies series, Jaffer expressed astonishment at the inclusion of Umran Malik.
“I am surprised with Umran Malik’s selection. We have seen him concede a lot of runs in T20 cricket. He is more suited to Test or one-day cricket. He needs to learn the art of T20 cricket. I do not think he is ready for T20 cricket.”
(With inputs from PTI)