Shikhar Dhawan was the first to turn up for batting practice before the toss of the washed-out first T20I between India and Sri Lanka in Guwahati. The capacity crowd welcomed him with boisterous chants of Gabbar ji! Gabbar ji! Gabbar ji! And the chants became louder when he punched left-arm throwdown specialist Nuwan Seneviratne on the up with a high elbow. Moments later, KL Rahul netted up and unfurled the right-hander's version of the shot and had the crowd cheering for him. For a brief while, the two openers matched each other shot for shot, entertaining the spectators before wet weather played spoilsport.

So, the second T20I in Indore will be the first round of a direct shootout between a fit-again Dhawan and an in-form Rahul for the second opener's slot behind limited-overs vice-captain Rohit Sharma, who has been rested for this series.

ALSO READ: Rahul 2.0 makes strong case for regular limited-overs selection

When Dhawan was out of action, Rahul staked his claim for a permanent role at the top, rattling off scores of 62, 11, 91 and 6, 102, 77 against West Indies in three T20Is and three ODIs respectively. Notably, the 91 off 56 balls came in the T20I series decider in Mumbai while the century came in a must-win ODI in Visakhapatnam. When Rohit took his time to get his eye in, Rahul teed off from the get-go and embodied India's new, attack-from-the-start approach.

Rahul has been given mixed signals by the management in the past few years. In 2017, Virat Kohli had said that they didn't want to forcefully make Rahul a middle-order option, but then India trialled him in the middle order in the Nidahas Trophy in Sri Lanka in 2018. Last year, Rahul started the 50-over World Cup in the middle order before an injury to Dhawan forced the team management to move him back to the top.

But now, through the sheer weight of runs in both international and domestic white-ball cricket, Rahul has made his top-order case too hard to ignore.

"Rahul has done really well for himself and it's good for the team as well that he's coming into his own," Kohli said on the eve of the series opener in Guwahati. "We know how good a player he is and what he can do with the bat. We are happy that he has got runs so consistently.

"When Rohit comes back, it's going to be a difficult thing to address because Shikhar is an experienced player but KL is playing so well. We have to decide the best combination to go with and what's the best XI we can go with."

Rahul has been the fastest starter among the three Indian openers in T20 cricket since January 2017, striking at nearly 128 off his first ten balls. Dhawan's strike rate in the first ten balls isn't too far behind in this period: 123.84.

Dhawan had a lean run in T20Is in 2019, but that could be because of the two injuries he had that year. In 2018, Dhawan was the top run-getter in the world in T20Is, with 689 runs in 17 innings at a strike rate of 147.22. He also sparkled for Delhi Capitals in IPL 2019 and emerged as their top scorer at home, on a tough Feroz Shah Kotla pitch, making 236 runs in seven innings at a strike rate of 130.38. Shreyas Iyer, who was the only other Capitals batsman to pass 200 runs at their home venue, struck at a shade less than 120.

Dhawan's overall T20 strike rate - a middling 123.58 - has become a talking point in recent times, but that's partly down to his role during his five-season stint at Sunrisers Hyderabad where he was to hold one end up and let David Warner be.

But more recently, in the second T20I against South Africa in Bengaluru last September, Dhawan did show greater intent at the top and took more risks than he usually does after India had chosen to bat first. He regularly flitted around his crease against South Africa's spinners and although he wasn't picking left-arm wristspinner Tabraiz Shamsi, he shimmied out and hoisted him for back-to-back sixes. However, when Dhawan attempted another six in Shamsi's next over, the spinner pulled his length back and had the batsman holing out.

When Dhawan was going through a lean patch in ODI cricket ahead of the 2019 World Cup, questions were raised about his form. Dhawan, though, bounced back spectacularly, with a well-constructed hundred against Australia.

Dhawan's weakness against left-arm pace is well-documented, but he found a way past that by standing on leg stump - and occasionally outside - staying beside the line of Mitchell Starc. He cleverly saw off Starc and Pat Cummins and went after the rest of the attack.

Dhawan's bouncebackability and pedigree in the ICC tournaments need no introduction, but Rahul's recent run and his range have heated up the race for the second opener's role in the T20 World Cup later in 2020 in Australia.

You can't really separate Dhawan and Rahul now, and you might not be able to do that after just two T20Is against Sri Lanka. The verdict will probably come in New Zealand.

Deivarayan Muthu is a sub-editor at ESPNcricinfo