Fernando Alonso is anticipating a "difficult weekend" for McLaren when the Formula One season starts in Melbourne after a troubled pre-season.

Two-time world champion Alonso was only able to complete 190 laps during testing in Barcelona due to issues with the MCL32's Honda engine.

Honda are optimistic they are making progress with the power unit, but Alonso is not expecting alterations to bear fruit for the Woking-based team at the Australian Grand Prix, with practice set to get under way on Friday.

"After a difficult two weeks of testing we're prepared to face a difficult weekend in Melbourne," Alonso said.

"We'll do our best with what we have and there's a lot of hard work and collaboration happening within the team, but the lack of time before the first race means you have fewer options for big changes.

"The first step will be to work on reliability before we can make any assumptions or predictions about performance, and we will try to enjoy the weekend as much as we can."

Honda's F1 boss Yusuke Hasegawa said they are doing all they can to address the issues faced ahead of the new campaign.

"In terms of performance, there has been room for improvement with mapping in order to have better driveability, and with further analysis we were able to make additional changes to be ready for Melbourne," he stated.

"We know we are heading in the right direction and we'll continue our efforts in order to increase our competitiveness throughout the season.

"Our priority for the weekend will be to extract the most out of our power unit, while maintaining reliability."