The Brazilian midfielder is known for his friendship with the Swedish star off the pitch and recently told reporters that working alongside him at PSG is helping him to strengthen as a player.
"Zlatan? He's crazy. But in everyday life he is rather calm and quiet," said Lucas, according to Goal.com.
"I appreciate being able to count him among my friends, and [working with him] helps me a lot with my football career... It's a chance for me to progress at his side."
PSG currently find themselves in second spot in the Ligue 1 table.