Agüero compared Ronaldo with his Argentine rival Lionel Messi, the American club Inter Miami's striker, saying: "The same applies to Leo. Their numbers cannot be compared."
He added: "I would have carried on because I prefer round numbers (1000, 900, etc.). I don't know whether it's superstitious, what we call 'cábala' in Argentina, or whether he hates odd numbers and wants to finish on an even number. I don't know."
Ronaldo has made a sluggish start to the 2026-2027 season with Al-Nassr. He's managed just three goals in seven matches, having netted three in five with Portugal at the 2026 World Cup last summer.
New coach Jorge Jesus, who was in charge of Al-Nassr last season, handed Ronaldo his first call-up after taking over as Portugal manager.
Ronaldo is expected to return to action in Al-Nassr's league clash with Al-Diriyah on 9 October.
Since joining the Saudi side three and a half years ago, Ronaldo has scored 132 goals in 155 matches.
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