Ferrari is keeping a close eye on Sergio Perez's performances at Sauber despite president Luca di Montezemolo playing down his chances of replacing Felipe Massa.Perez is a member of the Ferrari driver academy, whose head Luca Baldisserri told the team website that he had spoken to Perez before the Sauber rookie finished third in Montreal in June 2012.Perez earned his second podium finish in seven races; the other was in Malaysia in March.'MORE EXPERIENCE NEEDED'Baldisserri said: "After Monaco we had a discussion with Sergio. We wanted to find out why recent results had not lived up to expectations after the Malaysian GP. Perez is undoubtedly talented but he often lets himself down by being too aggressive which, especially in F1, does not deliver results."The Montreal race was a great response, a race in which Sergio not only ran at a great pace but also managed his race very well, staying on track for 50 laps on the same set of tyres."Perez also overtook Ferrari's double World champion Fernando Alonso, who ended up fifth and lost the overall championship lead, in the closing laps.Between Malaysia and Canada, Perez failed to score any points and finished 11th three times.Massa paid the price for an early spin and finished 10th in Canada and still looking a long way off his first podium finish since 2010. His contract will expire at the end of the 2012 season.Montezemolo told Reuters in June that Perez needed more experience and more good results before he could be put in a Ferrari.