WALES head coach Warren Gatland has made his World Cup selection stance clear after naming a 31-man squad for the tournament.

And that could even mean Wales captain Sam Warburton being in a battle for back-row recognition.

"We will pick what we think is the best team for each match we play," said Gatland, whose squad includes Exeter prop Tomas Francis, Bath lock Dominic Day and Bristol utility back Matthew Morgan, who have just four caps between them.

"If that means Sam isn't in the starting line-up, so be it. We have proved in the past we are willing to make the big calls."

Warburton's fellow number seven Justin Tipuric has already underlined his World Cup credentials with outstanding performances in two warm-up games against Ireland. He was man of the match in Dublin two days ago when Wales won 16-10 and Warburton missed out because of a shoulder injury.

"I thought it (against Ireland) was Justin's best performance in a Welsh jersey - not because of the things we know he can do, but because he did it up front," Gatland added.

"I have not seen him play that way, and he was absolutely shattered in the dressing room afterwards. I have seen that with Sam in the past. When Sam has been that exhausted, he hasn't been able to move for 30 minutes after a game.

"Ever since he (Warburton) was offered the captaincy - for the 2011 World Cup - it hasn't been about him, but the team.

"If I say to him, 'look Sam, I won't pick you, I am picking Justin', he will take that on the chin because the team comes first. That's the measure of the man, and we are very lucky to have that."

Gatland's squad contains five locks, with one of those - 90 times-capped Alun-Wyn Jones - currently from a medial knee ligament strain, while only two hookers have been selected in Scott Baldwin and Ken Owens, with Kristian Dacey missing out.

Gatland has also gone with wing Liam Williams, who has not yet recovered from a foot injury, and prop Samson Lee, who suffered an Achilles tendon injury last March.

Reflecting on Lee's current situation, Gatland said: "Maybe Samson for Uruguay (on September 20). He is up and running and not too far away, and it's just making sure we don't push him too hard, too early.

"Liam had a little bit of foot pain last week, and hopefully he will be up and running again this week. We have just got to monitor him."

The seven players cut from Gatland's 38-man training group are Dacey, flanker Ross Moriarty, Ospreys wing Eli Walker, Dragons centre Tyler Morgan, Cardiff Blues fly-half Gareth Anscombe, who is currently nursing an ankle injury, Blues prop Scott Andrews and Scarlets prop Rob Evans.

Gatland added: "We have ended up going for five second-rows, and really because it is such an attritional position, and as a result probably Kristian (Dacey) has been unlucky to miss out at this stage.

"Alun-Wyn Jones picked up a little bit of a medial strain on the weekend, which is a couple of weeks, Luke Charteris got a bang on the leg, so we have kind of looked at the squad and said that if players pick up knocks we've got cover for them.

"It's a couple of weeks (for Jones). That engine room is so important for us. I thought he was outstanding on the weekend.

"Some of the decisions were the toss of a coin. Those players that have missed out, you feel for them massively.

"It is incredibly disappointing for those players that miss out. It's hard, but you have got to accept that is the nature of professional sport and we are entrusted to make what we believe are the right calls."

Moriarty has missed out on following his father Paul and uncle Richard into a World Cup - they were both part of the 1987 campaign - and Gatland added: "Ross has come in and the more time he has spent with us, the better he has got.

"He has got himself into pretty good physical shape - he understands what we are looking for - but he has been unlucky. He is definitely going to be a player of the future."