Two-time Formula 1 champion Fernando Alonso is not exactly adding another impressive line to his racing resume with his return to the series this year, and he knows that winning races in 2021 is "impossible"at Alpine, according to those close to him.

Alonso's long-time manager and mentor Flavio Briatore told the Italian news agency Adnkronos that Alonso, who is returning to F1 after a two-year absence, was "disappointed" with the start of his comeback year. Alonso finished 19th at the season-opening race in Bahrain after exiting early with brake issues. He was not competitive before the brake problems popped up.

"I spoke to him on the phone," Briatore said. "He was disappointed, even though he knew that Renault's (the team is branded as Alpine this season) position would be this. They should focus everything on next year, even if working to recover when you are so far away is difficult. I think this year they will be between 12th and 15th places."

Four-time F1 champion Alain Prost, an advisor to the Alpine team, says 39-year-old Alonso understands the current potential of the team.

"Fernando is a perfectionist who demands a lot from the team," Prost told Le Figaro. "At the same time, he understands that fighting for victories on a regular basis this season is impossible. But I can say that he will definitely fight for every point."

Alonso, who turns 40 in July, told Sky Italia that he is committed to Formula 1 for "at least two years."

"After that, I'll have to see how I feel," Alonso said. "There are high expectations that with the new rules there will be more battles."

Alonso, who won championships in 2005 and 2006, has not reached an F1 podium since he finished second at Hungary in 2014. His last win in Formula 1 was the Spanish Grand Prix for Ferrari in 2013.