Wellington - Controversial short turnarounds at the Rugby World Cup do not, on paper, result in more injuries but they do lead to under-par performances from the teams involved, the Scotland doctor said on Friday.
Several of the "tier two" nations, like Canada, Georgia, Namibia and Samoa, have complained about their turnaround times between games - often only four days, which they say discriminates against them.
The top teams from the Six Nations and Tri-Nations tournaments in general have been accorded more time to recover between matches.
Rugby's global governing body, the IRB, said the match schedule took into account fan appeal, spread of matches across New Zealand and player welfare, as well as broadcast and commercial considerations.
"I think to turnaround in international Test rugby now, within four days is asking a great deal of the players that we are trying to care for," said Dr James Robson, long-time doctor to Scotland, and the British and Irish Lions.
"The minimum would have to be five days given that I think you need four days to recover. But ideally you’d want between six and eight.
"From a player welfare point of view, while absolutely cognisant of the commercial needs of world rugby, we do have to see if there's some other format for the future where we can have people playing with adequate turnaround time, and therefore performing at their best."
Nambia went down 87-0 to South Africa on Thursday just four days after a tough defeat against Samoa.
"We don't want to see games where Namibia get hammered 80-odd points to nil (although) that may just be the void in the skill gap," Robson said, adding that player recovery time would be on the agenda at a forthcoming IRB medical conference in London.
"I've been observing international Test rugby now for 20 years and I feel reasonably comfortable and confident in saying that I think, if we play on a Saturday at Murrayfield, it's Tuesday or Wednesday before I am really able to see the players able to train adequately and fully."
Robson, however, did not deem the short turnarounds "dangerous", but said they merely led to sub-standard showings.
"I don't think it's dangerous but I think it results in below-par performance," he said, pinpointing lack of conditioning of sometimes amateur players in second tier nations.
"If I say to the coaches 'you've got to be careful for the first couple of days when we get back to training in order to have the players available for the following weekend', well it must be an ever harder job for our counterparts in the Tier Two countries."
Robson added: "There's no good evidence to suggest that by turning around in four days you've got a greater injury rate.
"But it'll be interesting to see when the IRB analyse and publish the data from the injury survey this time whether there's any correlation between the teams of the players that are turning around in those small times.
"And even that would be only a very small study, so you can't say for definite."
Robson said players were "battered and bruised, they are quite sore and they’re quite stiff".
"It's a hard ask to do that and to perform at their best with short turnarounds and that's really where we want the world state of rugby to be at.
"We see it in most of the teams we play that people are getting better. As in the old adage, we have stronger, fitter, faster people so the collisions are bigger.
"We were for a while fearful that injury rates were going up but they seem to have hit a plateau, indeed dropped off a little. But that's only from studies that we’re seeing in the top tiers and we don't have evidence from the lower tiers."