Although Nasr was the only Sauber driver to score points last season, the Brazilian’s contract was not renewed at the end of the season.
He, however, hasn’t given up on a comeback.
“I’m still looking at options out there,” Nasr told Motorsport.com.
“The good thing is that I’ve been driving different cars in the past few months.
“I’ve been keeping fit, and it’s been nice to be in a racing car again.
“I still feel capable of being back here [in F1], and I’m looking at opportunities for 2018.
“Of course, F1 is Plan A, but there’s a lot of Plan Bs. It could be IndyCar, Formula E or WEC, these are all series that caught my attention.
“I’ll definitely be looking to try all I can before I make any commitments or any decisions.”
The 24-year-old, though, admits it is not easy given that there are only ten teams and 20 places available.
“It’s difficult,” Nasr added. “It would be nice to see one or two more teams around, not only for myself, but any up-and-coming driver that wants to step up to F1.
“But things can change very quickly as well.
“The important thing is I’m fit. I did everything I could to be ready for this year, and I know I can jump in any car any time, and show that I’m competitive still.
“It’s not easy to be out of the car, that’s for sure! But I don’t have any regrets. There’s a time for everything in life, and the important thing is that I’m ready, and I’ll make a decision pretty soon.”