Warren Gatland says Wales' priority is to make sure they are "a bloody hard team to beat" at the World Cup.

"If we're a hard team to beat, then things can happen for you," Gatland said.

"I stated before, don't write us off, this team is capable of doing something special and I still believe that."

Wales picked up the maximum five points from their opening game in Bordeaux and are favourites to triumph in Nice on Saturday, with Portugal playing in only their second World Cup.

With a six-day turnaround, Gatland said the new-look side have an opportunity to "stake a claim" to the shirt, with a match against Australia to follow in pool C.

"The players need to feel that if they go out and give a good performance then they are in contention to get selected for Australia, that's the only way you can do that," Gatland said.

Tight-head prop Henry Thomas is the only squad member not to feature in a matchday 23 so far this tournament and was not risked because he has a tight hamstring.

"He was going to start, we named him earlier in the week with Tomas Francis on the bench, it's just been a straight swap with Dillon Lewis," Gatland said.

The Wales coach said Faletau keeps his place as he missed the World Cup warm-up games and is a player "that gets better with more game time", while Gatland wants Rees-Zammit to keep playing as "he's been fantastic in the last five or six weeks".

After a review of the hard-fought Fiji game, Gatland said there were "a lot of positives and some things to work on".

"There's a lot been said about us in terms of how unlucky Fiji were, but we've seen a number of clips ourselves to say that things were missed in the game too," Gatland said. "Just to get clarity on that, the referees came back to us yesterday on those and we're in agreement with a lot of things that we'd sent in too.

"That game is done and dealt with, it's past us now and focus is now purely on Portugal and hopefully we will do a good job on Saturday then move on to Australia next week."

Portugal have had to wait an extra week for their tournament opener, with the pools consisting of five teams.

Gatland described the opposition as a "similar version of Fiji".

"They play a lot of rugby, they've got some exciting players, they like to move the ball around, so we're kind of prepared almost in the same way we prepared against Fiji, there won't be a lot of changes, a few little tweaks to the game," Gatland said.

"I thought from a neutral last week if you were watching the game, it was probably the most exciting game of the weekend in terms of the rugby that was played.

"It wasn't great being a coach sitting in the box in the last 10 minutes, I can promise you that, but hopefully we can produce another great game of rugby."

The Australia game on 24 September in Lyon is already being billed as the crucial match in Wales' progression out of Pool C to the knockout stages, with the Wallabies playing Fiji seven days before, but Gatland says they are not looking too far ahead.

"For us it's about one game at a time," Gatland said.

"We've always been confident in the past about World Cups and the opportunity to get the team together for an extended period, and we think that we have done well in previous World Cups and would like to get to a final of a World Cup.

"You get a group of players working for each other, putting that jersey on, that passion about playing for their country, passion about playing for for Wales, they recognise the history, what it means to the fans, the public and the families to represent your country, and if you get those things right then things can happen for you and that for us means a heck of a lot.

"I can promise you that when the guys go out in the weekend of any game they're going to give everything to play for their country.

"The first priority is to be a really tough team to beat and if we do that and get things right, and our preparation is good and we don't pick up too many injuries, then there's no reason why we can't continue to progress a long way into this tournament."