Those talks have not yet been successful but Whitmarsh says that his team will continue to push to secure an opening.
"We have tried at Force India, Lotus, and Marussia," explained Whitmarsh. "We have to get them into F1.
"I think they are both really, really good guys and both will get into F1.
"We have a duty of care to get them there. They are pretty special."
F1 faces long-term driver shortage
Force India's 2014 driver plans are up in the air at the moment, and Whitmarsh has suggested that a driver deal could be a factor in its discussions to extend a technical partnership it has had with the Silverstone-based outfit.
"They want to extend, but we haven't agreed to that," he said.
"But at the same time, I don't want leverage. One way or another we will find a way."
The other possibility could be for McLaren to risk promoting one of their drivers to its team next season, if it is not convinced by Sergio Perez.
Whitmarsh thinks that the lack of pre-season testing currently available in F1, however, means it may be too tall a task.
"I think it is a risk for them and for us," he said.
"We did it with Lewis [Hamilton] but, when you look back on the amount of running we could give Lewis beforehand, it was easier.
"You never know - but at the moment we are trying hard elsewhere.
"We had agreed to put Kevin into the Force India seat for the young driver test, and I shook hands with Vijay [Mallya] on it. But for some reason or other that didn't seem to bind him.
"Kevin was only put in at the last minute for us at Silverstone.
"He has had two runs in an F1 car [and] in Abu Dhabi, on his third flying lap, he did a time that was good enough for sixth on the grid, which is pretty impressive."