A month after his ACL injury, Rodri claimed the Ballon d'Or trophy, awarded to the world's best footballer of the year, after losing just one game for club and country and helping Spain triumph at the 2024 European Championship.
He returned to action in the penultimate game of the 2024-25 campaign against Bournemouth in May and played in all four games at the Fifa Club World Cup in the United States but endured an injury setback in City's shock last-16 defeat by Saudi Arabia side Al-Hilal.
Rodri then missed the start of this season and has featured in only eight Premier League and Champions League games so far, playing a total of 415 minutes.
He sat out Tuesday's thrilling 5-4 victory at Fulham, where Marco Silva's side threatened an incredible comeback from 5-1 behind.
"Rodri is another level of the players," added Guardiola. "If Rodri came on for the last 20 minutes against Fulham, put him in the middle and do you know what is the effect? Just his presence, not even touching the ball? The other 10 players feel safe and they play better.
"What will you do, you're a football player or you are a journalist, over 18 months you cannot do your job. You want to write, you want inspiration and show how good you are and you cannot do it. How do you feel? It feels bad.
"Of course, he is strong and in some moments he is sad. I would not be happy if he is not sad or concerned. Ahead of us, we have many nightmare things to live. He has to be there. He will be there."