Sainz, who is now in his third year with Ferrari, is pleased for Mekies as the Frenchman prepares for his next venture.
“Personally – because I can only talk from my personal experience – he is a top guy,” he said.. “Very valued, very strong figure. He’s taking a step up in his career so I can only be happy for him.
“I think, obviously, when you are offered such an important role, you have to take it.”
Mekies’ departure from the Scuderia follows the recent exits of team principal Mattia Binotto and head of vehicle concept David Sanchez, who will join McLaren next year.
However, Sainz is confident any gaps will be filled with the right personnel as Ferrari continues its pursuit of a first title of any kind since 2008.
“We are also hiring staff,” said the Spaniard. “It’s not like we are only losing, we are doing the best also to restructure our team, to make it stronger. And I’m sure there’s going to be people arriving to compensate for these last few losses that we have.
“It’s just that sometimes the losses are sometimes quicker than what you manage to get people back, but I’m quite confident with Fred’s [Vasseur, team principal at Ferrari] approach, the management and the way it’s being handled, because I see good things coming too.”