English rugby commentator Stuart Barnes has saluted the Irish touring squad for a series win that "stamped a psychological superiority all over New Zealand" — but he warned the result could spark changes that will make the All Blacks stronger at next year's Rugby World Cup.

Writing in The Times, the former first-five outlined the changes to coaching and playing personnel that could bring success for the All Blacks after "a forensic examination of the situation".

Barnes said the All Blacks are destined for failure at the World Cup if coach Ian Foster remains at the helm, adding "Ireland not only played, but coached them off the park".

"Foster seems set to fall," he wrote. "If he remains, New Zealand will fall at the quarter-final to either their Irish bogeymen or South Africa. If action is immediate and Scott Robertson is offered the post ASAP, the all-conquering Crusaders coach can galvanise a great rugby country.

"Robertson as manager and [Ardie] Savea as captain — with that combination in place I wouldn't be rushing to write off the All Blacks' 2023 hopes quite yet."

All Black coach Ian Foster and captain Sam Cane appear at a press conference. Photo / Getty Images

In his column, Barnes singled out the All Blacks No 8 for praise: "Ardie Savea, as in the first test, dragged his team back into the game with his combination of determination and skill."

He said the All Blacks "still possess some of the finest football players on this planet", highlighting the Barrett brothers and Aaron Smith.

"There is world class all over the place. But something has gone wrong."

"That something is off the field," he added, claiming that the All Blacks have "the wrong manager and the wrong captain in Sam Cane".

He also saluted the coaching efforts of Andy Farrell, saying "the last fortnight was a fabulous case of a coaching masterclass".

"An immortal rugby nation was made mortal by a group of men in green who will take on the tag of Irish immortality back on the Emerald Isle."

Stuart Barnes looks at the ball during the 1993 Lions tour. Photo / Getty Images

Barnes played against Foster on the 1993 Lions tour to New Zealand, the Mooloo men schooling the tourists 38-10. The tone for that match was set in the opening minutes when lock Brent Anderson used the Englishman as a rudimentary door mat in the build up to the hosts' first try.

Barnes noted how the Irish lineout had been pivotal to their victory, the first try coming with "a lineout drive through the heart of a dishevelled Kiwi pack".

After the first test, which was won 42-19 by the All Blacks, Barnes called for the selectors to sack captain Cane and play Savea as openside flanker.

Writing in his Times column a fortnight ago, Barnes said the No 7 "may be a fine leader of rugby players but he is not good enough to play for the All Blacks".