Fernando Alonso should consider leaving Formula 1 if he is unhappy, claims his former Ferrari team-mate, Felipe Massa.

There is a great deal of speculation surrounding the future of the double world champion, with his contract at McLaren expiring at the end of the year.

The Spaniard his also in the midst of his worst year in F1, having only finished one of the six races he has participated in as Honda's nightmare return to the sport continues.

"Fernando is complaining about F1 because he does not have a good car," Massa told Spanish publication El Confidencial.

"F1 is the same now as it was in the 80s," he continued.

"Now with Liberty we are going in the right direction to attract people, but with the cars, we still do not make a difference because the gaps between Mercedes and Ferrari and the rest is too great.

"Small teams should be given more opportunity, but until another Concorde Agreement is signed in 2020 it will be impossible."

Alonso returned to the F1 paddock at the Canadian Grand Prix after opting to skip Monaco and participate in the Indy 500 as part of a tie-up between McLaren, Honda and Andretti Autosport.

Though that, like many of his races this year, would end in an engine failure while competing towards the front, the 35-year-old was full of praise for the atmosphere generated in IndyCar both for the fans and by the media.

"In F1, everyone is looking for some controversy with what you say," he said in Montreal.

"Or thinking about the future rather than the weekends, because you already know who will be the top 15 in qualifying and the race."

Alonso has already said he wishes to remain in F1 after this year as a third world title remains his career goal, but Massa, who himself put off retirement for at least another year to remain at Williams, believes Fernando should consider his options carefully.

"I think it depends on a lot of things, but I think if you're not having a good time, it's best to leave," he said.

"He does not seem to be enjoying much right now, so maybe he will. Maybe he will go to another team or take on other challenges outside of F1.

"It's something we don't know," Massa concluded.