Fernando Alonso crashes out in opening hour of pre-season test

F1 testing is in full swing in Barcelona (2:31)

ESPN's Nate Saunders and Laurence Edmondson discuss what can be expected from testing as the first day kicks off in Barcelona. (2:31)

MONTMELO, Spain -- McLaren has encountered an immediate setback in its pre-season plans after Fernando Alonso crashed out on the opening morning of the first test.

Alonso was about to complete his sixth lap of the morning when the right rear wheel came off his MCL33, pitching him into a spin into the gravel at the final corner. The team later confirmed it was caused by a wheelnut issue. It is hoped Alonso will return to the circuit in the afternoon.

The incident will have been a blow to McLaren, having set itself the goal of completing at least 100 laps a day. The team is embarking on a new era with Renault power following three horrible years with Honda, which were often punctuated by reliability issues and performance issues.

In 2017, McLaren struggled to complete anywhere near enough running to be fully prepared for the new season. In total in accumulated just 425 laps in eight days. The problems with Honda were so severe at the time the Amazon documentary 'Grand Prix Driver' -- released earlier this year -- showed McLaren bosses had genuine fears Alonso would lose patience and quit on the eve of the 2017 season.