Sri Lanka head coach Chris Silverwood rued the lack of discipline from his bowlers after his side's 67-run loss to India in the first ODI in Guwahati.
Sri Lanka had put India in after winning the toss but Rohit Sharma and Shubman Gill seized the momentum for the hosts with a 143-run stand in just 19.4 overs. Virat Kohli then scored his 45th ODI hundred to help India post a daunting 373 for 7.
"Obviously, we didn't get off to the best start," Silverwood said after the match. "If I have to be brutally honest, our discipline in the first ten overs was lacking at times, and we allowed India to get off to a good start. This is a high-scoring ground. India knew that they had to get off to a good start and we allowed them to do that.
"They gained momentum from that and we had to push back all the time to try to put the brakes on. And I think we did that for a period of time. But when you have a class batting line-up as India have, then it's difficult to stop them."
Sri Lanka's fielding was found wanting as well. They dropped Kohli twice, first on 52 and then on 81. He went on to score 113 off just 87 balls.
"Yeah, obviously they were costly," Silverwood said of the dropped catches. "The moments like that are very critical in a game like this - we knew it was going to be a high-scoring one. And we all know if you give a player of Virat's calibre opportunities, he would take it. And that's exactly what he did today.
"Of course, it was an excellent knock but had we taken those opportunities he presented, you never know."
In response, Sri Lanka were 206 for 8 at one stage before their captain Dasun Shanaka added 100 with Kasun Rajitha in an unbroken ninth-wicket partnership. Shanaka finished with an unbeaten 108 but his innings only reduced the margin of the defeat.
Shanaka was Sri Lanka's highest run-getter during the T20I series as well. While Silverwood lauded Shanaka, he didn't agree the side was overly reliant on him, pointing out that Pathum Nissanka too scored 72 on Tuesday and added 72 with Dhananjaya de Silva for the fourth wicket.
"I think he [Shanaka] has done himself a world of good," Silverwood said. "He has put himself in the marketplace now. I am sure the [IPL] franchises will be looking at him [Shanaka was unsold at the auction] and seeing how dynamic a cricketer he is. He is a great striker of the ball, so hopefully, he will get an opportunity.
"[But] I don't think we rely [only] on Dasun. He is in a great vein of form at the moment, so obviously he is shining. If you look, we had Pathum also score runs today. I thought the partnership between him and Dhananjaya gave us some momentum when they were together.
"We have seen over a period of time that each individual at times has put their hand up and been counted. So I am not overly worried about that. Obviously, we need them to put their hands up more, especially on very good tracks like this, to put that fight up, to build partnerships. So that's a constant work."
With just one day's gap before the next game, Sri Lanka will also be fretting about Dilshan Madushanka's injury. The left-arm seamer had walked off when he hurt his right shoulder while trying to make a stop in the field. Silverwood said he would go for an X-ray to make sure everything is okay.