He had gone 24 innings without a fifty, His four most recent innings featured three ducks and a score of 5. But it was the intensity that Kusal Mendis brought to his fielding that tipped the team management off that a good innings might be around the corner. That was the reason why they refused to drop him for the fifth ODI.

This was what captain Dinesh Chandimal revealed following Sri Lanka's 219-run DLS victory over England in Colombo. Sri Lanka could have brought the experienced Upul Tharanga back into the side, after Mendis had registered scores of 0 and 5 in his other two outings of the series - never looking like the kind of player the likes of Kumar Sangakkara had predicted would go on to score 10,000 runs in ODIs and Tests.

But suddenly, in this match, a fire reignited in Mendis' game. His 56 from 33 balls was not the most substantial knock in Sri Lanka's innings, but it was the most eye-catching. He struck at a run-rate of 170 and hit six sweet sixes, the most attractive of them an imperious lofted off-drive off Tom Curan, in the 38th over.

"We looked at Mendis' fielding, and that was the No. 1 reason we trusted him," Chandimal said of giving Mendis another opportunity despite the lean run of scores. "His attitude on the field was great. We know that when you have a player like that, he can get into form very quickly. We know how good a batsman he is. Kusal Mendis is our future. He took that responsibility on and played well for the team."

Fielding, in general, has been something Chandimal has emphasised since taking the captaincy from Angelo Mathews, and in this series, Sri Lanka have seemed to raise their game on that front. Where in previous months, including in September's Asia Cup, Sri Lanka were perhaps the worst fielding side on show in any trophy they happened to be playing for, they arguably out-fielded England through the course of this series. At the very least, Sri Lanka were the more proficient side in Tuesday's game.

"The main thing for us is fielding," Chandimal said. "If you can keep that energy and good attitude when you are fielding, other things fall into place. That's what we did as a team."

Much as Sri Lanka would have loved Mendis to hit this kind of form earlier in the series, that he has done so with the Tests on the horizon will be an especial fillip to the hosts, who often look to him for top-order runs on turning tracks. Two other key Test batsmen were also among the runs in this game. Chandimal himself struck 80 off 73 balls - the first occasion since 2016 in which he scored more than fifty at better than a run-a-ball. Wicketkeeper-batsman Niroshan Dickwella, who opens the innings in ODIs, and bats in the lower middle order in Tests, made the highest score of the series, hitting 95 off 97 deliveries.

"We had lost the series when we got here, but we were intent on regaining form ahead of the T20 and Tests," Chandimal said. "I'm glad three of our Test batsmen made runs today. We're hopeful we can take that confidence in to those next two series."

Andrew Fidel Fernando is ESPNcricinfo's Sri Lanka correspondent. @afidelf