Angelo Mathews, 30 years old, former captain, once the owner of a fearsome average, now merely a very good one, potentially a great batsman still, but man, the last 18 months have not been kind.

For a player of such indisputable quality, it has been a strange decline.

Remember how he had been in 2014 - that last great year of Sri Lankan cricket - when out of nowhere, he hit a harvest so golden, so irrepressible, that he bludgeoned attacks into pulp, nurdled without relent, left no advertising board unstung by his boundary hits, and even when off the field, probably coughed up, sneezed and exhaled runs.

There was that monstrous 160 at Headingley, of course, when he threw his bat in anger at a team-mate's dismissal, then set about busting England up all by himself. There had also been a sweaty 157 not out to save a tough game in Abu Dhabi, and a difficult 43 not out to set up a victory at SSC. At times, Mathews seemed to have supernatural help. Having hooked Sri Lanka towards victory late on the fifth afternoon in Galle, against Pakistan, the furious black cloud that had bore down on a packed stadium held off its torrents until he was taking the winning run. He averaged 87.80 and played the lead role in a famous series victory in England. So thoroughly did Mathews own 2014, that Kumar Sangakkara scored more international runs than has ever been made in a calendar year, and still, quite happily admitted his captain had been the better batsman - prospering on every type of surface from greentop to dustbowl, producing every kind of innings from stonewall to sprint.

Now, three years between himself and his best work, Mathews finds himself surpassed. He was once the torchbearer for the next generation of great batsmen, but what's this? Four younger men have snuck by him, mounting hundreds upon hundreds in years in which he has not averaged thirty. And while Mathews had been stuck attending Sri Lanka's transition into transition into transition, each of Virat Kohli, Steven Smith, Joe Root, and Kane Williamson have taken the reins of happier, more confident sides. Mathews will be thankful for last year's Test series against Australia, at least, when he for once got the better of one of those younger men. Otherwise, since the beginning of 2016, his would have been one long, sombre vigil.

And this is perhaps the most unfortunate thing about the dip in his arc: where once leadership had unlocked the great batsman within him, the latter half of Mathews' captaincy so clearly wore him down. Every time he fronted up after a match and declared his team's performance to be "humiliating" or "embarrassing" or his "worst loss as captain" or "one of the lowest points" in his career, Mathews the batsman appeared a little more diminished in his next innings.

Angelo Mathews comes down the pitch during his career-best 160 Getty Images

There were no technical failures during this leaner period. Well, not really. He does occasionally hang his bat out against the seaming ball, and that had been the source of some strife in South Africa this year. But far worse has been the lack of conviction in his strokes, pushing tentatively even after he has struck firm boundaries, handing out soft dismissals to every team that rolls up - the recent caught-and-bowled to Graeme Cremer being a prime example.

For that Test - against Zimbabwe - Mathews had already handed over the reins, but there was still none of the old freedom about his game. When you are captain, you tie yourself so tightly to the team's fate, that maybe it takes a little untangling to feel your old self again.

India's last tour of Sri Lanka in 2015 was the last the world saw of Mathews the great batsman. In that series, he had averaged 56.50 on pitches favouring bowlers, and outscored India's best batsman - Kohli - by more than 100 runs.

In 26 innings since, 735 runs at 28.26 have been his returns. This, for a man who once mopped up top-order spills better than anyone in the world, wiped nervous sweat off tail-enders' brows and charged them to bat better in his company than they ever had before. And if all else failed, and a loss was certain, he would at least hit a few quick runs and make the scoreline more presentable.

Sri Lanka have no more need for Mathews the captain. As they prepare to face the top-ranked side in the world, Mathews the batsman they could use plenty of.

There is no better time to shed the despondence of the last few months. No better time to let the weight fall, and to discover the joy that once coursed through his game.

This time, do it for yourself, Angelo. It could be the best thing you do for your team.