Former dual-code international Jonathan Davies says that an injury to Lee Byrne would leave Wales short at full-back.
Byrne has made the 15 shirt his own and started the first Test against South Africa for the British and Irish Lions before injury curtailed his tour.
Wales have used James Hook at 15 when Byrne has been injured, but Davies says that Hook is then missed at centre.
"At the moment Lee Byrne is way out there and if he gets injured then [Wales are short of options]," he said.
"All the best full-backs the world's ever seen, it's no coincidence they've been specialists.
"I still think you need a specialist because your angles of running is one thing.
"Maybe you take high balls from the cross-kicks now as a winger but they're different from the high balls that the full-back takes, and of course you have to have a kicking game."
Wales' James Hook has taken centre, full-back and fly-half in his stride
Hook deputised at full-back during the 2009 autumn internationals when Byrne was injured, impressing in defeats to New Zealand and Australia, and wins over Samoa and Argentina.
Byrne returned for the 2010 RBS Six Nations campaign and was an ever-present in the starting line-up as Wales stuttered through the championship to finish with two wins and three losses.
One bright point of that campaign was the increasingly impressive midfield partnership that Hook was developing with Jamie Roberts.
Hook needed shoulder surgery over the summer but could return to Ospreys colours for next week's derby at the Scarlets.
Wales do have more options at centre, with the likes of Jon Davies at the Scarlets, Hook's Ospreys colleague Andrew Bishop and Blues veteran Tom Shanklin.
While Gatland would prefer not to have to break up his first-choice centre pairing to shift Hook to 15, should Byrne get either injured, banned or fall badly out of form, former Wales captain Eddie Butler believes that is the more likely path the coach would take.
"We have got some midfield cover now," said Butler, appearing as a guest alongside Davies on BBC Wales' Scrum V show.
"It has always worked against James Hook that he is so versatile but, in this particular set of circumstances, if Lee Byrne gets injured then I'd say he has to go back there.
Czekaj looks powerful and strong under the high ball, he's got a good left boot
"I like a bit of height on a full-back, he has to win the aerial contest.
"Lee Byrne is the perfect shape, he catches the ball brilliantly and the other thing is he's got this huge boot."
Chris Czekaj, who has seven Wales caps on the wing, has impressed for the Blues at full-back this term.
Experienced former Scarlets and Brive full-back Barry Davies, now with the Ospreys, could be another option but he is yet to return from a long-term groin injury that required to operations last season.
Davies is hopeful of returning to action sometime in October, saying: "It's good to be able to see the progress, it's been a long time but I think I'm coming towards the tail end of it now and I should be playing again before long.
"I've started doing a lot more running, more physical work and I'll hopefully be getting involved in some rugby sessions [in September]."
The Ospreys possess two more possible full-back options in youngsters Gareth Owen and Tom Prydie, who has won four caps on the wing but has played most of his formative rugby at full-back.
But with the likes of Byrne, Shane Williams, Tommy Bowe, Richard Fussell and Nikki Walker ahead of them in the Liberty Stadium pecking order, the pair have had to make do with bit-parts at regional level.
Owen came on for the end of the Ospreys' 38-6 win over Aironi on Saturday, while Prydie was starring for Swansea RFC in the Welsh Premiership - playing on the wing he scored a try, three conversions and a penalty in a 34-28 win over Cross Keys.
Highlights: Swansea 34-28 Cross Keys
Morgan Stoddart at the Scarlets is another to have been capped by Wales but has suffered badly with injuries.
Another option for Gatland in time for next year's Rugby World Cup could be provided by Gavin Henson, should the double Grand Slam-winner decide to end his 18-month exile from the game and return to playing in time to prove himself.
Newport Gwent Dragons possess potential future internationals in the shape of already capped Will Harries and Jason Tovey, currently injured, but it remains to be seen if they get the nod for this autumn's Tests against New Zealand, South Africa, Australia and Fiji.
"Will Harries I don't think has got a kicking game good enough and I think it would be sad if we lost Hook's creativity in the centre," Davies added.
"Czekaj looks powerful and strong under the high ball, he's got a good left boot... but how many games is he going to have with Ben Blair there [at Cardiff Blues]?
"If he breaks in and is number one well okay, he puts his hand up."
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