Mark Webber's admission last week that he held talks with Ferrari before opting to commit himself to Red Bull for 2013 suggests the Maranello marque are looking for a replacement for the Brazilian.
Massa, who is out of contract at the end of the year, suffered a dismal start to the season, scoring just two points from the opening five races.
There has since been improvement, with Massa finishing sixth in Monaco and fourth last time out at the British Grand Prix 10 days ago.
Although Massa's role is far from secure for next year, the 31-year-old said: "Of course I keep an eye on what is going on with other drivers, just as anyone likes to know what is going on in whatever work they do.
"But the only thing that is important for me is I keep performing in the same way I did in Silverstone.
"In the two grands prix prior to that, in Montreal and Valencia, I should have been entirely capable of finishing in the top five or on the podium.
"But for various reasons - a spin in Montreal and a problem with the floor of the car in Valencia - that did not happen.
"Without that, since Monaco, I would have been fighting for the top five at every race.
"I'm sure driving the way I am now is the only thing I can do and need to do to ensure my future.
"What happens in the drivers' market does not have a significant effect on my position.
"If I carry on performing the way I did in Silverstone, then I don't feel too worried about my future."
Ahead of this weekend's German Grand Prix at Hockenheim, Massa at least appreciates the 23 points to his name and 13th place in the drivers' standings are not good enough.
In particular given the fact his performances mean Ferrari trail Red Bull in the constructors' championship by 64 points.
With team-mate Fernando Alonso leading the drivers' title race, Massa knows he has to continue to improve.
Speaking on Ferrari's official website, he added: "The drivers' (championship) is still important to me.
"Looking at where I was just before Silverstone, I am aware there are a lot of points still available over the coming 11 races.
"It is very important for me and I want to fight to get back into the top six or top five.
"That might be a difficult target to achieve, but you always need to set yourself a hard challenge.
"In addition, the constructors' championship is very important to us, and the better I do in the drivers' the more I help Ferrari."