Wales wing Shane Williams says he is lucky to be back to face Ireland in the World Cup quarter-finals after his thigh injury.
And the record try-scorer says young players like George North and Leigh Halfpenny are boosting Wales' veterans.
"The older guys are doing their damnedest to get on the field and stay, keep up with these younger guys," Williams, 34, said.
While Williams is back, Stephen Jones, 33, loses out to Rhys Priestland, 24.
Williams, whose thigh injury ruled him out of Wales' Pool D games against Namibia and Fiji, paid tribute to wingers North, 19, and Halfpenny, 22.
"[They] have played exceptionally well so I'm lucky to be back in the squad," he said, adding that his thigh had not caused him any problems during the week's training, although he had been concerned.
"It was... something that possibly could have meant I was going home, but in fairness to the coaching staff and the medical side of it, they stuck by me and worked hard to make sure that's up to 100% fitness."
Wales face a stern test on Saturday against an Ireland team that have won all their Rugby World Cup matches in this tournament, notably beating Australia 15-6.
And Williams is convinced Wales' combination of experience, youth and confidence can triumph.
"It's the most mentally strong side I've been involved in as far as international sides are concerned," he told Scrum V.
"The self-belief coming into this World Cup was enormous and strangely when you look at how many youngsters are coming through, the confidence coming from these guys is just incredible and perhaps that's given the more experienced guys a lift.
"It's a massive game for us at the weekend but we know that if we can go out and play our best rugby we can win that game, it's as simple as that."
However, Williams does not under-estimate Ireland's threat.
"There's a lot of respect there for the Irish side, because they are a side that have given us problems for a number of years now.
"They're an experienced side, they know how to win big games, so we've just got to go out and give it our all.
"We've always been a side that's been able to play rugby, throw the ball about, but I think we're a little bit more clever in our approach, are far mentally stronger.
"My Ospreys team-mate Tommy Bowe has had a great tournament for Ireland so far, he always does.
"He's a predator in the game and he's a player certainly that's going to try and cause us problems on the weekend.
"So I'm going to keep my eye on him and probably he's going to keep an eye on me... Keith Earls, on the other wing for Ireland, is a deadly finisher so it makes for a good contest in the back three."