Ronaldo has scored five goals in his last three games for Real Madrid including a hat-trick against Sevilla and a goal in each leg of the Champions League semi-final defeat to Juventus.
That would be good going for most strikers in the world, but Sacchi is still not convinced the Portuguese is playing to his full potential.
Sacchi, himself a Real Madrid sporting director from 2004 to 2005, says Ronaldo is only continuing to score goals because he is a fighter but in reality he is not in good form.
"It's been three months since Cristiano Ronaldo got away from an opponent," Sacchi said on Mediaset.
"He scores, because he's a fighter, but he's not in form."
Unless it has been mistranslated, Sacchi is certainly sensationalising his opinion to get himself in the newspapers. Ronaldo has scored 55 goals in 50 starts for Real Madrid this season and recently equalled Alfredo Di Stefano's goal scoring record of 307 goals.
He is now only 17 goals away from becoming the all-time leading goal scorer for Real Madrid. On his current form surely he will reach Raul's record of 323 by Christmas.
The Real Madrid complex
Ronaldo is suffering from the Real Madrid complex, which inextricably links the player's success with that of the club's. The 30-year-old embodies the team so when the team fail, Ronaldo fails.
Real Madrid look set to narrowly miss out on the La Liga title to Barcelona and have failed to retain their Champions League title. That may see Ancelotti lose his job as manager, but will also see individuals take the blame.
Ronaldo is also constantly compared to Barcelona star Leo Messi. The Argentine has been in incredible form this season and is already being tipped to win the 2015 Ballon d'Or.
That would give him five Golden Balls in total, leaving Ronaldo with the impossible task of winning two more to match him. But while he may fall short of Messi, he will almost certainly retire as the greatest goal scorer for Los Blancos.
Is Ronaldo really in bad form?
Give us YOUR opinion in the comment box below!
Do YOU want to write for GiveMeSport? Get started today by signing-up and submitting an article HERE: https://gms.to/writeforgms
Do YOU want to write for GiveMeSport? Get started today by signing-up and submitting an article HERE: https://www.givemesport.com/writeforgms