Fernando Alonso has expressed concern that the DRS on his Aston Martin could again let him down following the failure of the system so far throughout his Azerbaijan Grand Prix weekend.

The system has only worked intermittently over the first two days, a thorny issue around a circuit where it is pivotal given the lengthy start-finish straight that provides a healthy overtaking opportunity into Turn 1.

Both Alonso and team-mate Lance Stroll experienced the problem during the sprint shootout, with the former again doing so during the sprint itself in which he finished sixth, just under 12 seconds behind race-winner Sergio Perez in his Red Bull.

As to whether the trouble will re-occur in the race, Alonso said: “That (the DRS) is the topic this weekend in our team. We’ve had problems every session.

“It did work (during the sprint). I pressed it two times in the race and it did open, so I hope everything is fixed.

“One time I wasn’t looking in the mirrors so I’m not sure but I’m sure the team is analysing all the available data.

“We cannot be 100 percent sure (it is fixed). I don’t think the system is bulletproof into the race, but it is the way it is.

“If we have some tweaks to do we have another chance before the race.

“But even with the DRS it seems very difficult to overtake when you are following so maybe it’s not the key factor even if it doesn’t work.”

Alonso podium run under threat

Alonso and Aston Martin have been the major surprise of the season to date, with the 41-year-old claiming three third-place finishes from the opening three grands prix in Bahrain, Saudi Arabia and Australia.

That run, however, is in serious danger of coming to an end in Baku as the car has been off the pace this weekend, whilst it appears one of the team’s main rivals in Ferrari has taken a step forward, certainly at the hands of Charles Leclerc.

“The weekend in general has been a little worse than the previous three races,” assessed Alonso.

“We are underperforming a little bit. The morning (sprint shootout) is the best example. P8 and P9 is not good enough.

“We were right to be concerned coming into the race (weekend) but for the race itself, I have to say I’m more optimistic now after the sprint that the car will be fast.

“I was fast in the sprint. I was faster than a Ferrari and Mercedes. I start P6 (in the grand prix) so we still have a chance to finish top five.

“That will be ideal if we can finish sixth on Saturday, top five on Sunday. On a difficult weekend that will be very good news.”