Fernando Alonso says he will have two metal plates in his jaw for the duration of this season after breaking it in a cycling accident last month.
The two-time champion will on Saturday drive a Formula 1 car for the first time since the incident.
"I don't expect any issues, honestly," he said. "One thing is the professional and driving side, which is 100%.
"On the personal, I will have to remove two titanium plates in the upper jaw at the end of the season."
The 39-year-old, who is returning to F1 with the Alpine team this season after two years away, said he had been forced to rest for "nine or 10 days" after breaking his upper jaw in a collision with a car in Lugano, Switzerland, but had been training "absolutely normally" for the past two weeks.
He added that he had driven in Alpine's simulator on Monday and Tuesday before flying to Bahrain for the pre-season test.
'F1 the place to be'
Alonso, who has won 32 grands prix and is regarded as one of the greatest drivers in history, left F1 at the end of 2018 to pursue other goals in motorsport.
He has since added a second victory in the Le Mans 24 Hours endurance classic to his debut win in 2018, won the World Endurance Championship with Toyota, competed twice without success at the Indianapolis 500, and tried the Dakar Rally.
He said he decided to return to F1 "because I felt I was at my best in the last couple of years; I felt I was driving better than ever".
"I had to make a decision on what was the next challenge after all the things I tried," he added.
"I thought being at my best now, maybe F1 was the place to be, and I have time in the future to rethink some of the challenges that were not completed. I felt I had something more to do here."
Alonso has an initial two-year deal with Alpine, the former Renault team, and said their goal was "to fight for wins and championships in the future" if the team could raise itself to that performance level.
Hulkenberg in talks with Mercedes
Meanwhile, Mercedes are in discussions with German former F1 driver Nico Hulkenberg about joining them as a reserve driver this season.
The world champions already have Belgian Stoffel Vandoorne and Dutchman Nyck de Vries as reserve drivers should Lewis Hamilton or Valtteri Bottas be indisposed, but they race for Mercedes in Formula E so are not available for three of the races.
Team boss Toto Wolff said: "Nico is a known quantity and well respected, so it would be good, but it's not yet [done]. We didn't put pen to paper."
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