The Spaniard, a triple winner in 2005, was - however - beaten to Barcelona's chequer by McLaren driver Kimi Raikkonen.
He admitted on Wednesday: "I think at the moment McLaren are a little bit in front of us."
Monaco, though, is an anomalous circuit, Fernando warned. "Last year," he recalled, "Ferrari dominated the whole championship but here they were not quick enough.
"(But) we do know the McLaren is quick."
Raikkonen, on the other hand, singled out 'traction' as one of the most crucial performance elements in the Principality.
And he said of the Renault R25: "(It is) usually very strong in that area (but) we should be able to challenge to win." -GMM