A despondent Lewis Hamilton says Mercedes are a "long way off" fighting at the front after a disappointing start to the season-opening Bahrain GP weekend, and admits he is not sure his team can close the "big gap" to Red Bull and Aston Martin with the "concept we have".
Mercedes, looking to bounce back from their shock 2022 downfall, saw their fears about their new car confirmed on Friday with Hamilton finishing Bahrain's first day of practice in eighth and George Russell 13th.
Fernando Alonso topped Practice Two for surprise new challengers Aston Martin, ahead of Red Bull, and Hamilton admits former eight-time world champions Mercedes already have plenty of ground to make up.
"We found out we are a long way off," said Hamilton, who was six tenths off Alonso's best time in P2. "We kind of knew that a little bit in the test but it is a big gap.
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"With Red Bull, looking at the long runs, they are a second a lap faster so we have got a lot to work on.
"I thought that the Ferraris were second but on a long run we are close to Ferrari. It looks like the Aston was second and we are kind of between third or fourth.
"So we are kind of where we were last year, if not a bit further behind."
Hamilton was also damning about Mercedes car concept - which the team have retained for this year despite the rest of the grid going in a different direction.
"It is difficult for everybody and it is really not where anyone in the team wants to be and certainly not where I believe everyone in the team deserves to be," he stated. "We are just on the wrong track.
"We have just got to continue to graft away and find a way to get ourselves on the right track.
"I have to be hopeful. There was good progress through last year but the gap wasn't as big as it is now.
"Do I believe we can close the gap at some stage? Yes... but I think it is quite hard with the concept we have."
Russell was similarly pessimistic about Mercedes' chances this weekend, with final practice at 11.30am on Saturday before qualifying at 3pm - both live on Sky Sports F1.
"There are a few teams out there looking strong, probably Aston Martin the biggest surprise so they have clearly done a very good job over winter," said Russell.
"It is still early days but clearly we want to be higher up the timesheet than we are, that is no secret.
"We need to find more downforce, find more lap time. But this is only our fourth day with the new car and we just need to make sure we have got it in a window where we are reaching it's full potential and right now, we haven't got it there."
Alonso hails Aston Martin start | Verstappen, Red Bull 'have work to do'
The surprise of F1 2023's opening day was undoubtedly Alonso, who led a team that finished seventh last season to the top of the timesheets in the representative evening conditions at Sakhir.
The two-time world champion, 41, beat Red Bull's Max Verstappen and Sergio Perez by a tenth and a half.
"Well, obviously it is another step in the right direction," said Alonso on Friday night. "The car still feels good but we need to wait and see.
"I think Lawrence [Stroll, team owner] has a vision on everything he does and it is very difficult to see Lawrence fail on anything that he has into his vision.
"It is a matter of time before Aston Martin can challenge top teams.
"We are in an interesting process with a completely new car, new technical department, and a lot of things we are learning... there is still a long way to go."
Verstappen, meanwhile, was surprisingly off the boil on day one, finishing third in P1 and second in P2.
"A difficult start of the day, Practice One was really bad," he said. "I just couldn't get the balance which was really odd because in testing, OK maybe some things were not amazing but not that far out."
But Verstappen added: "Then I think in the long run, with all the changes we made, I was quite surprised at the pace we had.
"Overall, the car is not too bad in the long run I just need to find my rhythm with the car again. We went back into the right direction and it is looking much better now.
"They [Aston Martin] are quick but you could see that in testing they were very competitive. "They had a great day and for us there is still work to do."
Ted: Alonso a contender for front row in qualifying
Sky Sports F1's Ted Kravitz in Bahrain
"There was good reason [Red Bull thought they were going to blow everyone away] because they had one of the best test sessions that they have ever had.
"They were leading two out of the three days and today, their pace has just disappeared.
"There were problems for the electronics for Sergio Perez which put him off, the handling wasn't correct for Max Verstappen so the set up has gone somewhere and they need to find where pretty quickly.
"We can say that [Aston Martin is a contender for the front row] definitely.
"It is a contender for the front row and single lap pace was the question really whether they were going to be any good and Alonso answered that question today in some style.
"We already know that his race pace is very good so Fernando Alonso a contender for front row tomorrow and a podium on Sunday."
Formula 1 is back! Watch the season-opening Bahrain Grand Prix live on Sky Sports F1 this weekend. Saturday's qualifying and Sunday's race are live at 3pm. Get Sky Sports