The Blues are likely to undergo a squad overhaul during the summer following a frustrating season and Luiz is one of the players who is strongly linked with a move away from the club.
"He has been out for two or three months with a knee problem. He was very good last year, it worked out well in the Conte line-up with three defenders," Alex told Goal.
"There are many defenders who like to play in this line-up. David Luiz did very well as a libero. Unfortunately, he did not start well this season. I'm not sure what happened, probably a problem, so he lost his place in the starting line-up. I'm very fond of him. He's a great friend, a great person.
"Could he leave? It's difficult to talk, every day you may be surprised... We do not know yet if the coach will continue. Sometimes a new coach arrives, and the player ends up receiving more opportunities. David is an experienced player. For me, he should not leave, because Chelsea is an exceptional club. I think he should stay and try one more time. For the quality he has, the player that he is, the opportunities will appear.
"I have seen great players, especially in my position, who lost their place in their teams, for example John Terry, a player I always saw as the best player in the world of my position at that time.
"[Luiz], due to injury and some other things, has also lost his spot. David Luiz is still a great defender, and he's not that old! You have to turn things around."