Mourinho told talkSPORT: "Kovacic I always feel he's much better than what people think.
"And I am very upset with him because he played in every club I've been, but never with me!
"So I love the guy and the guy followed my clubs… maybe he goes to Tottenham! Maybe he goes to Tottenham next season! But he never played for me."
Croatia ace Kovacic will face off against England on Sunday in their opening Euro 2020 clash at Wembley.