Rassie Erasmus shares a trait with Warren Gatland: honesty. He has been in charge of South Africa for less than two years, on detachment from his day job which is to run the professional game in the country, and taken a team who were not so much on the slide as careering uncontrollably downhill into one who are a victory away from a World Cup final.

Standing in their way in Yokohama on Sunday will be Gatland and his Wales team who have not lost a competitive match since February last year. The New Zealander is coming to the end of his 12-year tenure with two matches to go whatever happens this time, having turned a side who were a laughing stock into winners, as has Erasmus.

Like Gatland, Erasmus plays it straight so when he was asked whether one reason he had not selected Cheslin Kolbe, who aggravated an ankle injury and has been replaced by S’busiso Nkosi in the one change from the side who started the quarter-final against Japan, was the hope that the wing might be fit for the final six days later, he replied: “If I answer this, a few people will definitely write it up the wrong way. I hope they don’t because there are two reasons we did not pick him. The first is that it is better to have a fully fit S’bu, who has been playing well and deserves his chance, than Cheslin at 70%. And, if we get to the final as we hope, he may be fully fit.”

Then there was the question of his continued preference for a six-two split of forwards to backs on the bench which allowed him to bring in a fresh tight five so Japan could not exploit tired legs. “I took a few sleeping tablets to make sure it was the right call,” he said. “You are taking a chance but I have been involved in close games when the extra backline player was not used. Having an extra forward lifts our defensive system and takes pressure off the backs.”

And he was not afraid to say, as the coach of the only team in the last four who have lost a match here after going down to the All Blacks on the opening weekend, that he was not just looking at making the final but winning it. “We would loved to have beaten New Zealand but the bottom line is that we lost to the best team in the world. We did not press any panic buttons but kept on working and are sitting pretty to have a solid chance of reaching the final. We expect and want to go all the way to try to win it and we feel we have as good a chance as the other three teams.”

Listening to Erasmus openly reply to questions without smearing his opponents or the match referee, Jérôme Garcès, whose past 10 matches in charge of South Africa have yielded one victory for the Springboks and whose appointment sparked a petition there to have him removed, was to understand why the improvement of a side who in 2016 lost eight matches, has been as swift as it has been profound. Like Gatland, he has given his players direction and judged them on the present, not the past.

Admitting that Kolbe would be missed and that Nkosi and the left-wing Makazole Mapimpi were not the most experienced in the tournament, he said: “They are scoring tries and doing the job. That is why having a calm head in Willie le Roux at the back, who I know is copping a bit of flak lately, and we all understand why, is important in many aspects of the game.”

Erasmus was referring to Le Roux’s struggles under the high ball against Japan and a shocker of a knock-on that ended a promising attack, knowing that one of Wales’s strengths is their kicking game as they look to force teams to play from their own half. “Wales know how to exploit being in your half,” he said. “They almost have a southern hemisphere backline in terms of size and, with their great pack of forwards, it is a big threat. I do not know who the favourites are on Sunday but we believe we can beat them and they will believe they can defeat us. That makes for an entertaining game.”