The incident was the latest in a series of pitlane problems for the Swiss team who will become the Audi factory outfit from 2026.
It was the third race in succession that Sauber had suffered pitstop issues, with Chinese driver Guanyu Zhou (24) losing time in Bahrain with a cross-threaded nut and Bottas in Saudi Arabia.
"We had implemented mitigation measures for our pitstop issue, something that has improved the situation but, as we have seen, not completely solved the problem," said team representative Alessandro Alunni Bravi.
"What happened to Valtteri is a slightly different, but linked, issue compared to what happened in Bahrain or Saudi Arabia but one for which we paid a really high price and that completely ruined Valtteri’s race."
Bottas said it was clear the team still had work to do.
"It’s never great to see a good race come to nothing: it’s frustrating as, until the pit stop, things were going really well," he added.
"What we have done so far has reduced the incidence a lot, but the risk is still there as we have seen today.
"There’s an element of bad luck there, and there’s nothing the pit crew could have done differently, it’s a technical issue that needs to be solved."
Racing director Xevi Pujolar said the changes made since Jeddah were not to blame.
Race stewards found the team had "lost control of a wheel nut during a pit stop causing a potentially dangerous condition in the pit lane during the race."
