Bottas parked at the side of the road at the end of the pit straight, limiting his experience of the team’s major update package to test runs in the earlier session and just one flying lap on the medium tyre in FP2.
The Ferrari power unit, which was used by Bottas in the early races of the season, cannot be used again, pushing him towards grid penalties later in the year.
In Imola, Bottas suffered a broken exhaust and subsequent fire in Friday qualifying, and he was forced to miss Saturday’s FP2 session while repairs were undertaken. In Miami he had a huge crash in FP1, and had to sit out the later FP2 session.
Team boss Fred Vasseur said after the Florida race that Alfa needed to have a clean weekend in Barcelona in order to make best use of the update package.
The loss of valuable track time thus came as a blow, especially as the other car was shared by Robert Kubica and Guanyu Zhou, thus compromising the flow of feedback.
"Unfortunately, this seems a bit of a trend,” said Bottas when asked by Motorsport.com about his ongoing misfortune.
“We seem to have tricky Fridays. I think this time it seems like it was an engine issue. So all we can do is look ahead to tomorrow and try to maximise the session.
“It's nothing new for us. I'm sure we can still have a strong weekend, because based on that one lap that I had in FP2 the car felt good.”
Bottas confirmed that the team made a conservative start in the first session, opting for a higher ride height while running tests to ensure there was no porpoising with the new package before going lower later on.
“Based on that one lap in FP2 I can say that it seems to be working,” he said. “But FP1 it was difficult to judge, because I think we were quite conservative with the set-up in a way to try and avoid porpoising and everything.
“So we just wanted to gather the data in FP1. That one lap like I said to say it felt okay, so I think we can we can learn something even from a single lap like that, and at least Zhou got some long runs. I think we can still have a strong weekend.”
Vasseur admitted that the loss of an engine and track time was a double blow for the team.
“It even damaged the bodywork so we’ll have to repair it,” he told Motorsport.com of the PU failure. “It was the first one [used this year], so it could be worse, it’s not a disaster.
“But it’s a shame, because in FP1 we had to do a lot of tests, we didn’t do proper laps, and in FP2 we did only one lap. OK, it’s Barcelona, I think in two laps he will recover, and even the lap he did was a very good one.
“For sure it’s not an easy start to the weekend when you have one car split between two drivers, and the other one didn’t do a session. It’s not a drama, and I hope we have a clean weekend from Saturday onwards.”