MUMBAI, June 8 -- Going into the England Test series starting in Leeds on June 20, India's biggest concern will be over how the Shubman Gill-led side will cope after the retirements of Virat Kohli and Rohit Sharma. Who will step up in the batting line-up? It's a place which demands a lot of acclimatisation by the batters. When the sun plays hide-and-seek, on most days in England one is facing the moving ball in the cold and gloom. The two India A unofficial Tests against England Lions would have helped ease some nerves in the Indian camp. After Karun Nair's double century in the first game, KL Rahul hit a stylish century on Day 1 of the second game in Northampton on Friday. Dilip Vengsarkar knows what it takes to do well in England, having scored three centuries at Lord's, cricket's spiritual home. "The fact is you have to get acclimatised to the conditions quickly," says Vengsarkar. "We were fortunate that we got to play a lot of County games ahead of the series and also in between Tests. It was good practice - moving ball, seaming conditions, cold and gloomy weather of England. Once you get acclimatised and have runs behind you, then it is a beautiful place to bat. They are excellent wickets to bat on," says the former India captain who played 116 Tests and toured England four times (1979, '82, '86 and '90). The key, for Vengsarkar, was using the side games to get into rhythm. While India's main squad landed in England on June 6, Rahul made the effort to reach in time to play in the second India A game. The Karnataka batter benefitted. On his first day in the English summer, he crafted 116 while opening the batting. It was a satisfying effort on a green Chester-Le-Street pitch against an attack led by Test pacers Chris Woakes and Josh Tongue. Though he got a hundred, there was an important lesson for him - you are never set in England. His first lapse in concentration ended his 273-minute vigil when he played away from the body to a good-length delivery from seamer George Hill to be caught at second slip. The ball was 61 overs old, but Hill's delivery swung to take the edge. Vengsakar's advice? "You have to adapt to conditions quickly, because even after 80 overs the ball keeps swinging in the air and off the wicket. So, you have to be careful not to play big shots because invariably the ball moves (and) then you are gone in the slips, or caught behind. You have to push the ball for ones, twos and threes. It's important to stay side-on and not play big drives." While Rahul has cemented the opener's spot, the team management is undecided on the No.4 slot. Karun batted at No.3 in the first India A game in Canterbury, strengthening his case with a classy 204. Given the No.4 slot at Northampton, he scored 40 during an 84-run partnership with Rahul. For a team in transition, the experience of the two former Karnataka teammates could be vital. Rahul and Nair are both 33, but Nair is hoping to make a Test comeback after eight years. For a smooth transition, India need Rahul in the lead role. For a batter of his quality, an average of 33.58 in 58 Tests doesn't do justice. Being the most experienced batter in the side, the young team will look up to him. Those who have watched him from close say Rahul is extra-focussed now. That focus was evident during Friday's knock. The lesson for him from the last England tour is that when in form, make it count. In 2021, he made a difference in the first two Tests, but then his form tapered off. He started with 84, 26 and 129, but his scores in the remainder of the series were 5, 0, 8, 17 and 46. The first Test is at Headingley, where the ball swings. The high point of any series is Lord's, venue of the third Test. Not everyone has tasted success here, including Sachin Tendulkar, Sunil Gavaskar and Ricky Ponting. Rahul has. On India's last Test there, he struck a majestic 129 to set up a memorable win. "When you play at Lord's and it is a full house, the atmosphere is electrifying. It could unnerve the best players while it could bring the best out in some who can hold their nerves," sums up Vengsarkar....