Shaun Edwards accepts that Wales need to tighten up defensively as they build towards the World Cup quarter-finals.
The Six Nations champions have conceded eight tries in three Pool D games, while official statistics revealed a high missed tackle count against Fiji on Wednesday.
"I realised we missed 25 tackles, then I thought to myself, 'who did we miss those tackles on?'" Wales defence specialist Edwards said.
"Then I looked, and there were 16 missed tackles on both of their wingers (Josua Tuisova and Semi Radradra) who, let's be honest, are not the easiest human beings to tackle.
"If anyone has an A-Z on how to tackle Josua Tuisova, please send me it. They are incredible athletes. Obviously, there were too many (missed tackles).
"But we only missed nine tackles on the rest of the team. Those two wingers are exceptional.
"Having said that, looking at the rest of the competition, France (Wales' likely quarter-final opponents) also have incredibly talented individuals, similar athletes, and we do need to improve that situation."
Wales are back in action on Sunday, tackling Uruguay at Kumamoto Stadium.
A fourth successive win would make it the first time since 1987 for them to go unbeaten through a World Cup pool phase.
And they will be red-hot favourites to post a third bonus point victory from four starts, setting them up for a showdown with Les Bleus.
"They (Uruguay) are a good attacking unit, but we just have to turn up with the right attitude tomorrow and put in a performance that we can be proud of," Edwards added."
Edwards will again set the players a target of points conceded - they hit it against Fiji - and he said: "I set realistic targets because you have to realise there has never been as many points scored in rugby union as there is now.
"If teams get near your try-line, it's pick-and-go after pick-and-go. It is incredibly hard to get the ball.
"It's important I set realistic targets, which I feel like I do. In the first two games (against Georgia and Australia) we didn't hit them - we were one score off - but against Fiji we hit it.
"I think when you are playing teams who are in the top 12-ranked teams, it would be very unusual not to concede a try.
"But all I know is that a lot of the rules - and I am not saying it's a bad thing, it's probably good for the game - are pro-attack."
Edwards, meanwhile, delivered a positive update on centre Jonathan Davies, who suffered a knee injury in the Fiji match.
"The medics are working on him," Edwards added. "We don't feel like it's as bad as we first feared.
"There will be more news in a couple of days, but the medics are working hard on him and we are in a positive frame of mind with regards to him being involved further down the line."
Wales lock Adam Beard will complete his comeback from appendix surgery a month ago when he lines up against Uruguay.
The Ospreys forward had an operation in Cardiff on Wales' departure day to Japan, and he eventually linked up with the squad 10 days later.
"The road to recovery started when I flew to Japan, and I am fighting fit and ready for Uruguay tomorrow," Beard said.
"It was obviously a massive drama, but I was lucky enough that I had good people around me who supported me a lot.
"I am buzzing to get back out there with the boys, and we want to finish this group on a high with four wins."