Although Vettel quashed the latest round of rumours linking him to Ferrari at the end of last season, Mateschitz said he could understand how the famous Italian squad might ultimately prove attractive to Red Bull's star driver.
"If it would not work out with us anymore it would be senseless to try to keep him just because of a valid contract," said Mateschitz.
"If I were an F1 driver, my desire would certainly be to become a Ferrari driver.
"But right now this is no issue."
Mateschitz also defended Mark Webber, whose performances and mental strength were strongly criticised by Red Bull advisor Helmut Marko earlier this year.
Although Mateschitz agreed that the presence of Vettel in the sister car made it hard for Webber, he said Red Bull was "lucky" to have Australian.
"In some races he can show his full potential," said Mateschitz. "It is difficult for him to come up against Sebastian, but the team guarantees equal material and treatment for both drivers.
"When Mark is in his best shape, he is even hard for Sebastian to beat.
"We are lucky we have two real number ones."
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