Nantes are currently in a slump, having lost 4 of their last 6 league games and only won 1.
They suffered a dip at home, losing 3 home games in a row.
On the other hand, Metz are in good form.
Besides, Metz are unbeaten on away field, only with 1 loss in 6 away league games.
The AH line is in favor of the away side.
So Metz should earn our credit here.