The 47-year-old explained that he was happy for Cruz to be joining the cast as the character of Angelica because of how well she can act.
He told DS: "She's a serious force to be reckoned with, Penelope. We did a film together years ago called Blow - I could've said we did Blow together years ago. That really would’ve made [the headline].
"So we did this film Blow together and she's wonderful, really a treat. She's a heavy hitter, you can throw all kinds of things up into the atmosphere and she'll snatch up something and throw a curve ball back at you.
"She's very stimulating, she's someone I adore, one of my best friends. It's been great having her.”
Depp, who plays Jack Sparrow in the series of films, also discussed his approach to playing the character for a fourth time.
He added: "I mean I honestly think this whole thing about characters and character arcs and 'finding themselves' and this and that, I honestly think old Captain Jack found himself a long time ago. I don't think there's any more room to - he can't go any further, I think he's hit a wall as it were."
Pirates Of The Caribbean: On Stranger Tides is due out later this year.
> Click here to read our interview with Johnny Depp