Kubica "didn't show his best" in first Williams tryout

Kubica first drove for Williams in Abu Dhabi, but after analysing the candidates, the Grove outfit opted to take Sergey Sirotkin for this season.

However, Kubica's performances in FP1 sessions and testing in 2018 convinced the team to hire him as George Russell's teammate.

"It's never that easy to chose drivers on a technical basis," said Lowe.

"And actually if you look in the past very often what they weren't picked on a technical basis, team principals were just sort of put a finger in the air and decide they like the look of somebody and then give them a job.

"So we went through a pretty careful process, and from that picked Sergey. I believe that was the right choice. But within that process I don't think [Robert] was able to show his best.

"And I think that's been disappointing to him all year, but I think 12 months later we've been able to see, get to know him better and see what he can contribute and how he can perform.

"So that also supported the decision that we made.

"I think, even as we've done it, the amount of data is quite limited. So I think, like many things in life you do the best for the data you have, and than you make a decision, and see how it works.

"We are 100% committed to both George and Robert, and once we become committed and they become 100% part of the programme and we work with them, they work with the car, than you know, that plays out, and we see where it takes us."

Lowe is confident that Kubica's physical issues will not hold him back.

"It is clearly something we had to consider in the selection, because you can't pretend that is not an issue, or potential issue. But now we've made our decision and we are confident that Robert is absolutely top class and ready to return to F1.

"I don't even think about it any more, it is just not a factor.

"Robert is our driver, he's 100% competent, he is 100% committed, we're 100% committed and we'll just go with that. Maybe other people from outside may bring that up, but it is not even in our minds."