Pep Guardiola confirmed that Manchester City will be without Rodri for the entire season after suffering ligament damage last weekend.
In a major blow to City’s hopes in the title race, the central midfielder had surgery in Madrid on Friday morning.
Guardiola suggested that Rodri suffered injuries to his anterior cruciate and meniscus and warned City must be careful with his recovery to thwart further issues down the line.
City had taken two opinions from experts in the UK and Spain, hoping that initial fears around an ACL were unfounded.
‘His season is over,’ Guardiola said. ‘Unfortunately he got the worst [outcome]. But it is what it is. Unfortunately at this level, it happens. We are there to support him, and he will recover step by step and move forward.
Rodri will miss the rest of the season after undergoing knee surgery in Madrid on Friday
‘When you have an ACL injury, it’s nine months and then you have muscle injuries the season after. We have magnificent players and will find the solution.
‘A lot of months without an important player for us, everybody knows it.'
The Spaniard sustained serious ligament damage during the first half of City's dramatic 2-2 draw with title rivals Arsenal last Sunday.
Following deliberation with the club, Rodri chose to take to the operating table, with renowned sports surgeon Dr Manuel Leyes performing the surgery, according to Spanish media outlet Relevo.
The Spaniard is a highly regarded orthopedic surgeon within the Spanish football community and City have decided to stand by Rodri's decision to be treated by him.
Real Madrid stars Thibaut Courtois, Eder Militao, and Arda Guler all underwent successful knee surgeries executed by the Spanish doctor.
The injury is a major blow to the champions with Rodri becoming a pivotal part in their recent successes.
Last season, four of City's five losses in all competition came when Rodri was missing through either suspension or injury.
However, speaking following a 2-1 win over Watford in the Carabao Cup, Guardiola was keen to not use Rodri's extended absence as an excuse in their attempts to defend the Premier League title once more.
'We don't want [Rodri's injury], but we will still have a good season,' said Guardiola. 'I trust a lot in my players. I have a duty to find a solution.
'Rodri is irreplaceable and the team won't play with the best midfielder in the world for a long, long time. Of course it's a big, big blow for us.
'It's football, it's happened, and my duty is to find a solution, to be competitive like we have been for many years.
'Rodri is not here, it's a problem. But complain? I feel sorry for him. Recover best as possible, we wait for you, and go for it. This is the challenge. Go to Newcastle, try to win, do what we have done for many years. Simple as that.'