The 30-year-old had initially been selected in the starting lineup but approached head coach Andy Farrell on Thursday to report his symptoms.
Ringrose has 67 Ireland caps but he is making his first tour appearance with the Lions, a team comprising players from England, Ireland, Scotland and Wales. The tours take place every four years and rotate between Australia, New Zealand and South Africa.
A concussion caused Ringrose to miss Saturday’s 27-19 win over Australia. The centre returned on Tuesday in the 24-19 over the First Nations and Pasifika XV (a team made up of players of First Nations, Maori and Pacific Island heritage), coming on as a substitute in the 65th minute.
Farrell said on Thursday that Ringrose had been picked to start on Saturday but after training, he withdrew from selection due to persistent effects from the concussion. Huw Jones will now partner Bundee Aki in midfield.
“It’s head-related again, so I actually don’t know at this stage (what’s happened),” Farrell said at a press conference. “It was literally as I was walking off the field, he came to me, and once it’s mentioned, that’s that.
“There was no incident, he was feeling good well in advance of Tuesday, fit and ready to play. No incident through the game at all, nothing yesterday and nothing this morning at all.
“But with these things, players are getting very good at telling the truth of how they feel. So it was a no-brainer to make the change straight away.”
Lions captain Maro Itoje called Ringrose’s actions “selfless”, with Farrell adding: “It was very big of him and the right thing to do, 100 per cent. For the team as well, not just for Garry.”
Ringrose plies his trade for United Rugby Championship club Leinster (Charles McQuillan/Getty Images)Headway, the brain injury charity, described Ringrose’s decision as “momentous for sport”.
“By flagging the ongoing effects of his brain injury, he has put the team first by stepping aside — allowing a fully-fit team-mate to take his place in one of the most high-stakes matches of the tour,” the charity said in a statement on Thursday.
“By recognising the risks of playing while concussed, Ringrose has rightly prioritised his own health. In doing so, he is also setting an incredible example to other sportspeople at all levels.
“His act shows how far sport has come in understanding the short- and long-term implications of not treating concussion — or brain injury — with respect.
“It also highlights how difficult it is for medics to accurately assess players for the concussion — both in the immediate aftermath of a collision, and then the lingering effects, which can last for months.
“It takes players to be open and honest, admitting when they do not feel right. It takes incredible bravery, but it’s a decision that could make such a difference to his long-term health.”
Luke Griggs, chief executive of Headway, added: “Garry’s decision is incredibly brave. It’s also selfless and potentially transformative in the way sportspeople at all levels consider brain injury.
“In doing so, not only has he protected himself from a potentially much more serious brain injury, but he’s also set an incredible example for others.
“Looking after yourself and looking after your team are not mutually exclusive. No concussed player will be an effective team-mate, and no game is more important than your long-term health.”
World Rugby launched a brain health campaign in November 2021 “to educate and support current and former elite players who might be concerned about their wellbeing and brain health”.
Former France international Sebastien Chabal said this year that he cannot “remember a single second” of his career. Now 47, Chabal appeared 62 times for France between 2000 and 2011, helping them win the 2007 Six Nations Championship.