Fernando Alonso appears to be stepping up his bid to return to Formula 1 in 2021.

The Spaniard, who quit McLaren and F1 at the end of last year, is back in the paddock in Abu Dhabi.

One observer even saw the 38-year-old, who will tackle the Dakar rally and the Indy 500 next year, in conversation with Liberty Media officials.

Alonso then told reporters that he is keeping the door to F1 open for 2021.

"I'd welcome an older dude, he can come along," smiled Lewis Hamilton, 34, in Abu Dhabi.

"Fernando's obviously a well accomplished driver and it's interesting when drivers want to come back like Michael (Schumacher). It's something you've done your whole life.

"I haven't spoken to Fernando so I don't know how he's been feeling or how much he's missed it, but I don't think it would be bad for the sport," the Mercedes driver added.

However, Hamilton cautioned that Alonso's comeback would mean a seat is taken up that could otherwise give a young driver his break in Formula 1.

"There's a lot of young kids on their way up and there's only 20 seats, so he has also had his period of time here," he said.

"But if there's no other good youngsters coming through then there is definitely space here that probably could be replaced. So I would welcome it."

Red Bull's Max Verstappen added: "It would be good to see him if he could come back in a competitive car.

"Otherwise I think it's just a waste of time for him, but I think he knows that himself."