Le Havre revealed the tragic news on Saturday, expressing their "deepest condolences" to the player's family.
The message was posted on the club's Twitter account, and reads as follows:
"It is with great sadness that we announce the death of our player Samba Diop.
"This is an extremely difficult time for all of us.
"The entire HAC club extends its deepest condolences to the Samba family."
7 April 2018
Diop was a member of Le Havre's reserve side, and was the vice-captain of France's U19s team. The cause of death is unknown at this point.
Le Havre's game against Stade Reims, which was due to be played on Saturday, has been postponed.