Olivier suffered one of the worst moments of his career on Sunday when he bowled an over that cost 32 runs in the T20 defeat to Derbyshire at Emerald Headingley.
It changed the momentum of a match in which Yorkshire had relative control before Derbyshire pulled away to score 207-5, Yorkshire then dismissed for 152 to slip to the bottom of the North Group after just one win from nine.
Olivier, 27, has blown hot and cold in the first of a three-year Kolpak deal, but director of cricket Moxon said: “I think Duanne will be better next season for the experience that he’s getting this season of playing day-in, day-out in England.
“He’s still learning about the conditions over here, and it’s a learning process of how to be consistently successful in English conditions.
“What happened against Derbyshire was just another learning curve for him, and I’m sure he’ll come back stronger for it.
“Duanne’s first two overs were fine; then, after getting hit for a six from the first ball of his third over, which was also a no-ball, followed by a free-hit that also went for six, it meant that he conceded 14 runs off one ball, which put him under pressure right from the start.”
Olivier, who forsook a promising Test career to sign for Yorkshire, having taken 48 wickets in 10 Test appearances at 19.25, has been more effective so far in red-ball cricket.
He is actually Yorkshire’s leading T20 wicket-taker this year with six at an average of 31.83, albeit with an economy rate of 11.23 runs per over, but he has performed more respectably in the County Championship, where he has captured 29 wickets at 34.89.
“Duanne has had some really good spells at times,” said Moxon.
“Certainly in the Championship, he’s got his fair share of wickets, and he’s still learning the balance of trying to bowl fast and play that enforcer role, for the want of a better phrase, in terms of when to implement that and when you need to bowl a fuller type of length.
“It’s still work-in-progress, but we’ve got a very good set of traditional English seamers at the club and there are times when you need to have something that little bit different, which is what Duanne gives us.
“He probably gets wickets for other bowlers too because he does give us something different, and he certainly has the ability to take wickets and unsettle batsmen.”
While Olivier remains a work-in-progress, so do Yorkshire in T20 cricket. Although only three points off the top-four qualifying places, it would take something remarkable for them now to reach the knockout stages, and they have decided against bringing back Nicholas Pooran, the West Indian batsman/wicketkeeper, for their final five games.
Reflecting on the T20 campaign so far, Moxon said: “We know what we’re trying to do and, at the minute, we’re underperforming in T20, we know that.
“Ultimately, we have to play better and learn to cut out the mistakes.
“If you lose momentum in T20, it’s hard to get it back sometimes, and when you’re not getting the results, sometimes that little bit of fear and anxiety can creep in, and it can almost go from bad to worse and you just need a win really to give you that confidence back and hopefully you can then go on a bit of a roll.
“It can be a cruel game, T20, when it’s not going for you because everything happens so quickly and decision-making has to be good under pressure.”
Moxon felt the display against Derbyshire was symptomatic of Yorkshire’s T20 campaign.
“We lost our way with the ball in the middle of their innings but we actually clawed it back at the end, I thought, because at one point they could easily have got 220/230 possibly,” he said.
“Batting-wise, the problem as ever with chasing big totals is that it’s very hard if you keep losing wickets.
“From six overs out on Duckworth-Lewis, we were actually winning the game, but we’d lost too many wickets from our point of view.
“The performance was symptomatic of our T20 season in that there were too many errors which cost us the game.”
Yorkshire fast bowler Jared Warner has rejoined Sussex on loan for the rest of the season.
Warner, 22, is returning to Hove after his spell there earlier this summer was ended by a side strain.
The Wakefield-born Warner will link-up again with former Yorkshire coach Jason Gillespie and is available for Sussex’s last four County Championship games, starting with Sunday’s match at home to Middlesex.
“I enjoyed my time there earlier in the year and I’m just looking forward to hopefully playing some more first-team cricket,” said Warner.