Sauber does not believe its strong end to the 2013 Formula 1 season cost it any ground in 2014 preparations.
After only scoring seven points in the first half of this year, Sauber made a performance breakthrough and took 50 points in the remaining races, overhauling Toro Rosso for seventh in the constructors' championship in the process.
Tom McCullough, the team's outgoing head of trackside engineering, said the step forward had not required a prolonged technical push, so Sauber had still been able to devote resources to 2014 while regaining ground this year.
"To be honest, we haven't changed a lot on the car [late in the season]," he told AUTOSPORT. "We had one big update package.
"We started the work on the 2014 car, CFD and aero work, a long time ago.
"Yes, we had to do a little bit more on the 2013 car than we wanted to but there has been a team working very hard on that and a lot of the lessons we have learned with sorting out this car will apply to next year's car as well.
"From the resources we are playing with, we have been lucky not to have to put too much focus on this year's car."
McCullough said Sauber's recovery had been a case of making adjustments to extract the car's potential, rather than the original design having been fundamentally wrong.
"We still look at ourselves and think we didn't do a good enough job at the beginning of the year, that's clear," he said.
"But we understood what the main problems were and focused our resource to improve those and we saw those gains coming.
"A lot of stuff was very right but there were a few small things that weren't.
"The track engineers and drivers just iterated away, understanding and improving, and we ended up getting a car into Q3 since Monza and had a car that deserved to score points every race."
Although McCullough's departure from Sauber has not yet been made official, AUTOSPORT understands that he is bound for Force India.