Rodri was named Euro 2024 Player of the Tournament as he helped Spain win the cup and played a key role in helping City win their fourth consecutive Premier League title last season.
He has lost just one game for club or country in the last 18 months and also won the UEFA Super Cup and Club World Cup with City last season.
Since joining from Atletico Madrid in 2019, City have lost just 11% of games in which Rodri has played, compared to 24% without the Spaniard.
“If a team cannot play with the best midfielder in the world for a very, very long time, it is a heavy blow,” said Guardiola.
“Yes, he is irreplaceable. But I will find a solution. There is an alternative, we will use it. When you have a player who is irreplaceable, we have to find a solution as a team.”
This month, Rodri said it would be “a dream” to win the Ballon d’Or, awarded to the best player in the world.
He played 63 times for City and Spain last season and, after missing the start of this season with a thigh injury, he returned against Brentford two weeks ago.
Rodri claimed players were “on the verge of” going on strike because the number of games on the calendar was being increased. The new Champions League format will include at least two extra games before the knockout phase and the Club World Cup has been expanded to 32 teams.
