The Republic of Ireland may not possess the deepest playing pool but the manager, Martin O’Neill, could still make 11 changes to the team which was defeated by Scotland last Friday and would certainly have been pleased that his two debutants impressed in a convincing 4-1 win over a similarly experimental USA.

Robbie Brady scored twice from left-back and the returning Shay Given, who came out of international retirement in September, made a couple of important stops with the score at 2-1 but it was the new faces – the Derby defender Cyrus Christie and the Ipswich striker David McGoldrick – who left the greatest impression.

McGoldrick created Ireland’s first two goals with a pair of delightful passes and left the field to a standing ovation after 76 minutes while Christie produced a confident display at right-back, making regular jaunts into the USA half and linking up well with Anthony Pilkington in front of him, to leave O’Neill satisfied.

“They had two excellent debuts and I think they epitomise what we are trying to do here, which is to have a squad full of quality players,” O’Neill said. “McGoldrick was getting a bit tired later in the game – he hasn’t had a pre-season – but made a great contribution with those two assists and Cyrus was really outstanding going forward for us.”

McGoldrick’s first involvement was an exquisite through-ball in the seventh minute which was met by Anthony Pilkington. The Cardiff winger glided on to the pass and nonchalantly lifted the ball over the head of the USA goalkeeper Bill Hamid to open Ireland’s account.

The USA enjoyed plenty of possession but it took a while before they showed signs of penetrating an unfamiliar Irish back-line. Their first notable opportunity arrived after 20 minutes when Alejandro Bedoya spotted Fabian Johnson unmarked at the edge of the area and the defender struck a sweet left-footed drive towards goal, only to be denied by a post.

Jürgen Klinsmann was disappointed with the outcome, leaving the US with one win from their past eight, but warned his team to expect more pain as he looks to blood the next generation.

“I’m not in a good mood right now,” Klinsmann said. “We saw some good stuff and a lot of not so good stuff. We are building now, we are introducing new, fresh players into the group and there will be growing pains. Obviously you don’t want to lose games but the development of these players does not come without pain.”

They should have led when Jozy Altidore hit the bar three minutes before half-time, having equalised through Mix Diskerud, but in the end were outclassed in the second half.

Diskerud’s goal came when David Meyler ceded possession too easily in midfield and the subsequent ball forward broke to Altidore on the left. The Sunderland striker, captaining the USA, fizzed in a cross which was knocked back by Chris Wondolowski, and Diskerud capitalised on some slack marking to send the ball into the bottom right corner.

Once Ireland retook the lead, courtesy of a moment of brilliance from McGoldrick, who spotted Brady carrying on a run from deep and found the Hull player with a deft backheel, the USA looked second best. They might still have snatched a second equaliser – Bobby Wood was denied by Given’s outstretched left boot on 66 minutes – but Ireland were consistently a far greater threat and Shane Long, on as a substitute for McGoldrick, hit a post after a fantastic dribble on the left nine minutes from time.

Confirmation of Ireland’s victory arrived seconds later, though, as James McClean’s low left-footed shot took a heavy deflection off Geoff Cameron en route to the bottom right corner. Brady added the fourth with a stunning free-kick which looped over the wall, leaving Hamid totally stranded, four minutes from time.

“Robbie was on a hat-trick from left-back,” O’Neill added. “He has things to improve on as a defender but he is an excellent footballer and has a great attitude. I was delighted for him. For him to be following up for our second to score from left-back was brilliant and he was so confident at that point that I felt he would score from the free-kick.”