Ronaldo, who won his fourth Ballon d'Or earlier this month, signed a new contract at Madrid in November, extending his commitment to the club until 2021.
But the cash-rich Chinese league has emerged as a major contender in the world transfer market with mega-money deals.
Last week, Shanghai SIPG signed Brazil midfielder Oscar from Chelsea for around 52 million pounds ($NZ92 million), while on Thursday former Manchester City striker Carlos Tevez joined Shanghai Greenland Shenhua when it was claimed he will become the highest paid player in the world on the equivalent of 615,000 pounds ($1,084,000) a week.
"The Chinese market is a new market," Mendes added. "They can buy a lot of players, but then again it is impossible to go for Ronaldo. Cristiano is the best player in the world and best ever. It is normal to have some offers.
"He won the European Championship with Portugal, it's like winning the Italian league with Genoa: they were not the favourite."
- AAP