Not to worry, at the end of an afternoon pounding out the laps in long run trim, 93 in all, Alonso gave the McLaren diehards reason to hope with legitimate effort to finish best of the rest, half a second down on Kimi Raikkonen's Ferrari.
Red Bull's best time on the hypersofts - Daniel Ricciardo's lap of 1:18.047 - was nearly a second shy of Ferrari's, but Thursday's cooler temperatures were more conducive to fast times.
Kimi Raikkonen kept Ferrari at the top of the timesheet mid-day, on the final session of pre-season testing in Barcelona.
Mercedes had the most productive day, with Lewis Hamilton and Valtteri Bottas sharing driving duties to clock up 201 laps between them, as they focused on running the harder tyre compounds rather than chasing lap times. Obviously there's always things to improve but that's normal with any car; even if you win races there's always things to improve.
McLaren was forced to change the engine, but this time Alonso didn't emerge again by 1pm - and unlike on Wednesday he had not completed a lap time before the stoppage either.
Conoce Tri rivales en Mundial Sub 20 Femenil
La justa tendrá 16 equipos compitiendo por el campeonato, que iniciará el próximo 5 de agosto y terminará el 24 del mismo mes. Las paraguayas ya conocen a sus rivales.
Alonso registered only seven laps before what looked to be an oil leak prematurely ended his morning. But Raikkonen, a veteran of 15 years in F1, says there is no point in reading too much into the times until the opening round of the season in Australia. The team did a total of 785 laps.
The Woking-based outfit's reliability issues set in once again with Fernando Alonso stopping on the track at Turn 7 with an apparent engine issue after 5 laps and just after posting the fastest first sector of the morning.
Robert Kubica forfeited his final morning of running at Williams, which swapped its run plan and put Sergey Sirotkin in the car first ahead of Lance Stroll taking over this afternoon. "It's been a good beginning with the new car".
Nonetheless having spent almost five hours kicking his heels as his crew changed his engine following a turbocharger issue, second and 0.563s off the pace is surely a lot more than the two time world champion was expecting a few hours earlier. For sure far from perfect with the weather last week. "But I feel like we've got as much information as we could in order to equip us with the best data to go to the season opener".
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