Fernando Alonso is still not ruling out a potential return to F1 for 2020.
The Spaniard quit at the end of last year but in Bahrain has agreed to test for McLaren in the post-grand prix test.
"It came up because my team could use a second car for Pirelli," said the former two-time champion.
"I guess they thought it is a good opportunity for me to try the car but not take the driving time of the other drivers," Alonso added.
However, the 37-year-old insists he is not missing F1.
"I've been too busy for that," Alonso smiled. "It might be different if I was sitting at home on the sofa."
Indeed, Alonso has won Daytona, tested a Dakar rally car, and later this year will contest the Indy 500 and Le Mans.
As for his F1 return, Alonso said: "I don't plan it.
"When I said goodbye, it was because I achieved what I wanted to in formula one.
"I have fantastic opportunities outside of formula one, and I wanted to get started on them.
"But if there is a fabulous opportunity (to return), then I would think about it. I never close any doors," he added.