The Spaniard has consistently scored more points than his Ferrari colleague since joining the Italian team in 2010.
The two-time world champion told Autosport.com: "Sure, it is not the first time I have helped him and surely it will not be the last. We help each other continuously, for the good of Ferrari.
"Felipe is one of the best drivers in the world. I have been repeating this for three years, and at times people look surprised when I say this during press conferences.
"These last few seasons there was a gap that I never had [with teammates] in the past, and points-wise it was something strange, because usually we should have been on a more equal level as far as points are concerned."
Massa supported Alonso towards the end of the 2012 season, including taking a controversial gearbox penalty to move his teammate higher up the grid at the US Grand Prix.
The Brazilian signed a one-year contract extension with Ferrari during the 2012 season, ensuring he will drive alongside Alonso during 2013.