Joe Denly might have expected his first Test hundred to come before his first Test wicket but England's late bloomer is confident a big score is just around the corner.

It is little more than a year since Denly re-emerged on the international scene, plucked out the county and franchise system by national selector Ed Smith after a decade off the radar.

His improving record as a leg-spin bowler helped him win a place on the 2018 tour of Sri Lanka, but since making his Test debut in Antigua 11 months ago, the 33-year-old's primary job description has been as a top-order batsman.

The Kent man has shown an aptitude for the stately rhythms of the five-day game, facing over 100 deliveries in eight of his last 12 innings, but a top score of 94 leaves a notable gap on his CV.

He chalked off a different landmark on the dramatic final day of England's second Test win over South Africa in Cape Town, opening his account with the ball via a disputed outside edge by Dean Elgar and a reckless shot from Quinton de Kock.

Compared to Ben Stokes' force-of-nature all-round performance, Denly's was a gentle one but it still went a long way to settling a match decided by slender margins.

"It's nice to be able to chip in here and there with a few overs and pick up wickets like I did in second innings," he said.

"I like to consider myself more than a part-time bowler, I feel I have something to offer. Certainly on day five pitches, when there is a lot of rough outside the off-stump to the left-handers I can play a part. It's nice to do that when the opportunity comes."

What Denly really needs, though, is a century. He came within spitting distance during the final match of last summer's Ashes and has passed fifty on six out of his 23 knocks in England whites.

Having frequently completed the hard work of getting set at the crease he has so far been unable to go on.

His conversion rate at first-class level, where he has 29 hundreds and 62 half-centuries, offers some hope and Denly is confident he can soon get over the line.

Speaking ahead of next week's third Test in Port Elizabeth, he said: "I'm certainly becoming more confident with each game I play, each knock I have.

"I'm feeling more and more confident when I'm out there. It is frustrating that I haven't kicked on and got that really big score but I really believe it is just a matter of time if I keep doing the things I've been doing.

"It will be nice to go on and get that big one an hopefully it is not too far away."

If he does manage to join England's hundred club before the end of the series, he seems unlikely to do so in a hurry. His present strike rate of 39.82 positions him as a considerably slower scorer than the famously watchful duo of Sir Alastair Cook (46.95) and Jonathan Trott (47.18), but for a player with a successful history in Twenty20 franchise cricket, that is clearly a choice.

Denly has plenty of shots at his disposal but, with the likes of Joe Root, Stokes, Ollie Pope and Jos Buttler to come, takes an admirably selfless stance on his role at number three.

"It's about being solid up front and building partnerships to allow these guys in the middle order to come in and play the way they can play," he said.

"As a top-order batter you obviously want to bat time: it is a case of understanding the game situation.

"There may have been times in the game when I could have got on with it a bit more but I think it is just having that game sense, trying to get the bowlers back for more and more spells in their legs. That allows our long batting line-up to take advantage when they are tired."