The 20-year-old made it four goals in two games in Saturday's 3-1 win over Borussia Monchengladbach.
And Lebouef thinks signing Havertz is wiser than the older Coutinho.
Leboeuf told ESPN: "I like his maturity on the field, he looks like someone who is 30 and knows exactly what he has to do and when he has to do it.
"The goal he scored was very clever, between the goalkeeper's legs. He's the master orchestrator of that team and I talked about him last week and I said that's a player that I would hire for sure.
"When we were talking Chelsea about Coutinho, when you see that player [Havertz], he should be in the Premier League very soon. He should be because he's a very, very talented player."