Johnny Sexton passed fit for Ireland's second Test against New Zealand

All Blacks will be without Sam Whitelock and Tupou Vaa'i for Saturday's match in Dunedin

Johnny Sexton receives medical attention during the Test Match between New Zealand and Ireland at Eden Park. Getty

Ireland captain Johnny Sexton is available for the second Test against New Zealand in Dunedin on Saturday after being passed fit having sustained a suspected head injury in the opening match.

Sexton was taken off with a suspected concussion during Ireland's 42-19 defeat to the All Blacks in the series opener in Auckland last weekend but assistant coach Mike Catt confirmed the 36-year-old fly-half will be available for selection.

"Johnny is fine," Catt told reporters on Tuesday. "Johnny is fit, Johnny has passed every test that he needs to pass so from our point of view he's good to go."

Sexton was not allowed to return to the field on Saturday having failed an initial Head Injury Assessment (HIA).

Following the game, however, Ireland head coach Andy Farrell refused to rule Sexton out of the rest of the series as the flyhalf had passed the second of three HIAs.

While Catt was relieved that Sexton would be available at the weekend he also praised the performance of his replacement, Joe Carbery, in Auckland.

"(Sexton is) a massive cog in there but I think Joe came on and did well," said Catt.

"We got back up again and this is what touring is all about, our ability to adapt to what gets thrown at us and I think we've done that pretty well. So I hope it continues."

In New Zealand team news, locks Sam Whitelock and Tupou Vaa'i have been ruled out of the second Test.

Whitelock, who became the All Blacks' second-most capped player at the weekend, could also miss the third Test in Wellington on July 16 after reporting a delayed onset concussion following the opening win over Ireland at Eden Park.

All Blacks turn on the style to beat Ireland

World Rugby's new head injury protocols preclude players from being selected 12 days following a concussion.

"It's not ideal," All Blacks captain Sam Cane told reporters. "Sam was awesome in the weekend. He became the second most capped All Black of all time which is hugely impressive.

"We'll no doubt miss his leadership and what he brings."

Coach Ian Foster will also be without Vaa'i after he tested positive for Covid-19.

Patrick Tuipulotu has been called up as a replacement following his recent return from a six-month stint in Japan.