Fernando Alonso left the door open for a possible return to Formula One on Thursday when he explained he was saying goodbye to the sport, but could not forecast the future.

The two-time world champion, who it is claimed turned down an offer from Red Bull before announcing his F1 exit, said: “I don’t have a crystal ball to know the future. For me, it’s a bye-bye, but who knows in the future.”

“Right now I am thinking that it is a goodbye, but life changes very quickly and life also taught me in the past how things may change in a couple of months’ time or in years’ time,” said Alonso.

He told a news conference ahead of this weekend’s Belgian Grand Prix that “it was a decision that probably I started thinking about last year.

“And then this year, 2018, there were a lot of changes into the team and with the engine manufacturer changes and things like that.

“I thought it was worth staying one more year. I enjoy driving these cars with new regulations, big tyres, more down-force and this year was some kind of joy to keep racing and to have another go.

“A couple of months ago, I decided it was the right time. I feel strong, feel a good level and want to say bye-bye to this sport when I am strong, not when I am not competitive or have no place to go.

“I prefer to take my own decision and take new challenges that Formula One cannot offer me at the moment.”