Sauber CEO Monisha Kaltenborn has revealed that James Key's departure from the team wasn't unexpected and has denied that there were any financial reasons behind the split.

The team confirmed last week that Key was to leave his role as technical director to return to the UK, with the team electing not to replace him but instead to hand extra duties to a range of people within the current Sauber set-up.

Speaking during the launch of the new C31 in Spain, Kaltenborn revealed that the relationship with Key had been strained for some time and the split was a result.

"For a while both sides have been feeling that things have not really been working out and also not [in the way] both sides had expected, I guess that this situation is now a result of that," she was quoted by ESPNF1. "James Key joined us at a time when we were in the transformation from a works team to a private team and his contribution was very valuable to the team and we are very thankful to him for that. We now have a structure in place that we are confident about and one that is the right one for the team to go ahead. So it's not a short-term solution for us but a long-term.

"The situation was not fitting well for a while so then you start considering what can you do? But now the people in charge of the performance of the car have already been there, so they have been in charge of it before as well and we don't expect any kind of destabilisation to happen. Moreover, the car is ready, we know what our plan is so we really don't expect this. We are not looking for a replacement because we are convinced the structure we have is the right one for the team."

Kaltenborn also added that the decision not to replace Key wasn't in any way financial.

"There are articles around that state we will not replace our technical director because we apparently lack funds," she said. "Just to be very clear and open here, I think if we look back 20 years the team has always lacked funds. The gap is maybe this big or this big or maybe smaller, but it was always there. I think you will see the day when there is no gap in our budget because then we will be near the front. I think it's easy to monitor and I just wanted to clarify that situation once and for all."