Before clocking the slowest lap of the day at Jerez on Thursday, Schumacher – the out-of-work former Toyota racer – insisted that he only decided to travel to the Spanish circuit because of an earlier "promise" to his friend and team owner Vijay Mallya.
But referring also to Schumacher's fellow beleaguered F1 veteran Giancarlo Fisichella, Gascoyne said: "I don't think they were here to be benevolent to us.
"They want to be involved in the team. But pounding around in winter testing isn't glamorous, so we were looking for someone who's got the desire and commitment," the Briton, who is the Silverstone's based team's chief technology officer, is quoted as telling the Daily Mail.
Gascoyne suggested that, among the younger contenders, both drivers are still in the running for the seat.
"The younger guys will get in the car for free and drive to their limit. But can they compete at the same level? When you've won races, like Ralf and Fisi have done, you've proved your ability," he added.
"There could be a trade-off between youthful exuberance and experience."
Mallya, the Indian billionaire who recently bought Force India from Spyker, says he will decide the team's 2008 lineup before Christmas.
"But there won't be an announcement until the new year," he explained.
"I need to balance talent with experience, and I need to find out how the engineers feel on driver feedback."