The Australian jockey partners the Medaglia d'Oro five-year-old at his race return in the $400,000 Group 2 Chairman's Trophy (1600m), three months after his disappointing eighth place to Mr Clint in the Group 1 Dester Singapore Gold Cup (2000m) in November.
Duric, who just captured a third consecutive Singapore champion jockey title, has been spending some time with King Louis since he's been brought back to work. He said he could feel an increment of improvement every time he jumps on him in trackwork.
Duric, who counts one association with iRace supremo Steve Levar's stable star for an unplaced run to Hong Kong's Southern Legend in the Invitational Group 1 Kranji Mile (1600m) in May, said there was no comparison between the horse then and now.
"I first rode him early doors in the Kranji Mile, but he is a lot more mature now that he's older," said Duric.
"He has improved every time I ride him in his work. He trialled really nicely the other day (close second to Wonderful Knight last Thursday).
"He just keeps getting better and better. (Trainer) Ricardo (Le Grange) and (assistant-trainer) Jacci (de Tert) have done a good job to keep him in good form.
"It would be handy if we could get a little bit of rain on Saturday, some cut in the track would help his chances.
"Then again, it would help all of the other horses in the race as well. There is no standout in that race, it's an even race."
King Louis, who had Perth champion jockey William Pike up at his last four starts, all in Group assignments, will actually renew rivalry with five of his Singapore Gold Cup rivals in the Chairman's Trophy, a feature race still missing on Duric's resume. They are Mr Clint and Sun Marshal, who are also resuming for Lee Freedman, Countofmontecristo, Gold Strike and Bahana.
Duric said he had no hesitation in accepting when Levar rang him up for the ride as he was actually not booked on any horse.
"Steve has been trying to get me back on King Louis, but I was committed. This time around, I was available and I was only too happy to get a good ride like that in a $400,000 race," said Duric who on Sunday steered Levar's Kranji debutant and much-vaunted Churchill to a cracking second to Absolvido in the last race.
"He was quite stiff last year, got beat narrowly twice, once by a nose with me on I'm Incredible (in the Group 1 Queen Elizabeth II Cup). It could have gone either way that day.
"He's a horse who is better off at weight-for-age conditions and there is no reason why he can't run a good race this Saturday."
At his fourth season at Kranji, King Louis has built up a reputation as a proven middle-distance performer, racking up four wins (1200m, 1600m, 1800m and 2000m) in 22 starts, including one at Group 3 level in the El Dorado Classic in 2018, but has often been luckless at the elite level – with a third in last year's Group 1 Singapore Derby (1800m) and that nose-second in the QEII Cup the most agonising among his defeats.