James Ryan cleared to lead Ireland against Japan

He will therefore lead the side out and take his place in the second row alongside Ultan Dillane against Japan, but there remained speculation about whether Gatland had asked Farrell about drafting Ryan into the Lions mix.

"Myself and Warren have communicated quite a lot, I know that Warren really rates James but the injury was a little bit of a setback, we didn't quite know where we were up to with that," Ireland head coach Farrell said.

"I informed (Gatland) that there was something going on and the medics took over from there. James, over the last day or so, in particular, has surprised everyone with the speed of his recovery.

"I'm delighted for James that he's able to captain the side. It's something that he's unbelievably passionate about. Hopefully that stands us down the years as well as far as the captaincy and the leadership is concerned."

Asked if Ryan would have been available for the Lions if he was fully fit, Farrell said: "I don't know whether that would have been the case but there's always conversations that have to happen before decisions like that are made."

Seven Ireland players are on Lions duty while regular captain Johnny Sexton, along with Cian Healy and Keith Earls, is sitting out the Japan fixture as well as next weekend's clash against the United States.

Stuart McCloskey will earn his fifth cap as he joins Chris Farrell in the centres for a game where around 3,000 spectators are expected in Dublin, the first time fans have been allowed into the stadium since February last year.

Hugo Keenan starts at full-back with Leinster team-mate Jordan Larmour and Ulster's Jacob Stockdale on the wings, while Jamison Gibson Park and Joey Carbery are at scrum-half and fly-half respectively.

Peter O'Mahony will be at blindside flanker, joined in the back row by Josh Van Der Flier and Caelan Doris, while Ronan Kelleher and Finlay Bealham will sit alongside Dave Kilcoyne in the front row.

Gavin Coombes is among the replacements – joining Rob Herring, Ed Byrne, John Ryan, Ryan Baird, Craig Casey, Billy Burns and Shane Daly – and the Munster back rower is the only uncapped member of the 23-strong squad.

"I'm excited across the board to see how the team performs because there's so many different ramifications that are happening throughout the side," Farrell said.

Only Keenan, Stockdale, Kilcoyne and Van Der Flier have been retained from the Ireland side that last took the field in a 32-18 win over England in the Six Nations in March.

Ireland were memorably defeated by Japan in their most recent encounter at the 2019 World Cup pool stage, and Farrell is once again wary of a Brave Blossoms side that has had plenty of time together ahead of this game.

"By all reports they've been together for six weeks, it's a big block," Farrell said. "We've been together for 12 days come matchday. That's not us complaining because that's the world we're living in in the northern hemisphere.

"If you look at the Japanese side, I though it was the best prepared team at the World Cup bar none and their performances showed that.

"I believe they had an unbelievably long stint together before that and the players they've picked to come over on this tour, a lot of them were in that squad."

Japan have made three changes to the side that were beaten 28-10 by the Lions at Murrayfield last weekend, with the uncapped Semisi Masirewa starting on the wing, allowing Kotaro Matsushima to replace Ryohei Yamanaka at full-back.

Naoto Saito is set to feature at scrum-half while Kazuki Himeno will be Japan's number eight.

Japan head coach Jamie Joseph said: "We know at home (Ireland are) very strong, a lot stronger than when they're away, so it's a different kettle of fish and that's something that we've been consistently talking about all week."