Fernando Alonso declared himself happy with his qualifying performance which saw him miss out on Q3 by a tenth, and cannot wait to attack in Sunday's race.
The Spaniard is due to start P10 on the grid in Australia as Mercedes expect Valtteri Bottas to drop down the order because of a gearbox penalty due to his Q3 crash.
"It's what we deserve and I'm happy with it," Alonso told Sky F1.
"I think we have huge potential to unlock in the car.
"We still have some issues before we unlock everything so I think in the next coming races we can look forward to the season very optimistic."
Alonso would love rain to fall in Sunday's race, but he is most looking forward to finally being able to attack with Renault power as opposed to just surviving with a Honda engine in years past.
"It's going to be a different race for us – more in attacking mode and it's going to be fun," he added.
"Especially if it rains tomorrow, it's going to be amazing for the show."
Vandoorne also missed out on Q3, but he is encouraged by the long-run data and also thinks McLaren can have some say in the race.
"We are in reasonable shape for tomorrow, we had some good long-run pace and hopefully we can get some points," Vandoorne said.
"We're in that group with a few teams that are very, very close together. Hopefully we can make a little bit of a difference in the race tomorrow."