The newly-promoted side were beaten by an 88th-minute Marko Maric header just minutes after Momar N'Diaye had equalised for Metz following Michel Bastos' opener.

The loss was Metz's second in as many Ligue 1 outings this season, and Diop believes his colleagues need to maintain their concentration for the full 90 minutes to avoid getting punished for minor errors.

"Everyone needs to get it in their heads that we are now in this division," Diop told www.fcmetz.com. "We will be made to pay for small mistakes because there are opportunist players out there who will make the most of them.

"Small things can make a big difference and we need to improve our marking, if we can solve those problems we will start to win games."