McLaren's Fernando Alonso has told fans that he is well after crashing heavily in testing last weekend - but no decision has been taken on whether the Spaniard will compete in the 2015 Formula One season-opener in Australia.

Alonso, who crashed his McLaren in pre-season testing at the Circuit de Catalunya, spent three nights under observation in hospital in Barcelona before being released on Wednesday to recover fully at home.

The 33-year-old spoke publicly for the first time since the accident in a video message posted on YouTube, saying: "As you can see, I am completely fine.

"I would like to be at the test this week in Barcelona but the doctors' recommendations are to wait a little bit, a couple of days.

"I will rest this weekend and keep you updated next week with progress."

Denmark's Kevin Magnussen replaced Alonso for the final pre-season test at the Circuit de Catalunya but McLaren expect the double world champion to take his place on the starting grid for the first Grand Prix of the season in Melbourne on March 15.

"Alonso is physically well and I see no reason why Fernando can't be in Melbourne, but I'm not a doctor," Ron Dennis, chairman and chief executive of the McLaren Group, said earlier this week.

"Fernando wanted to return to testing (the car) but the doctors have told him that if he wanted to be certain, he needed to rest and have medical follow-ups."

"There will be some tests, there are processes laid down within the FIA, and I can't see any reason why he won't sail through."

Meanwhile Marussia's return to Formula One has been approved by the sport's FIA governing body.

The revived Manor team issued a statement earlier this week confirming their intention to contest the 2015 season opener in Australia after announcing they are to enter a Company Voluntary Arrangement that will see them emerge from administration.

Manor also announced Will Stevens as their first driver for the new campaign and now the FIA has approved their entry for the 2015 season.

"Their application to compete has now been formally approved by the FIA, subject to the team's full compliance with the 2015 regulations and to Stevens' holding of a Super Licence," the FIA said on its official website on Friday, naming the team as Marussia.

The identity of Manor's second driver has not yet been confirmed but it was announced earlier this week that an investment group spearheaded by the former Sainsbury chief executive, Justin King, had struck a deal with a long list of creditors that should allow the team to continue.

"It's very exciting to see everything coming together at Manor after the tremendous effort that has gone into saving the team," Essex-born Stevens, who drove for Caterham in the last race of 2014, said earlier this week.

"It would not have been possible without the incredible support we have received from all the suppliers and from within the sport, but most of all the fantastic team of people at Manor who are working around the clock to ensure we are ready for Melbourne."

Manor confirmed they are working feverishly to finish off their car for 2015, which will again run with Ferrari-supplied power units from last season, and to be on the grid in Melbourne from March 12-15.