Vincent Pajot’s goal before the break put the home side ahead but Les Verts couldn’t keep hold of their advantage and Nantes drew level in the second half when Emiliano Sala struck.
The result means Saint-Etienne are 12th in Ligue 1, while Nantes are up in fifth but M’Bengue was not particularly happy with the point.
“We were leading 1-0 and we slipped in the second half,” he told beIn SPORTS. “In our situation, we had to keep the lead. We take a point, but we cannot be satisfied with that.”
Northampton striker Kevin van Veen is hoping to make his first start in over a month in the home game against Shrewsbury.
Derby's decision to postpone Sunday's home Sky Bet Championship game against Cardiff was made independently, Derbyshire Police have confirmed.
Rochdale have no new injury worries ahead of Tuesday's Sky Bet League One relegation battle with fellow strugglers Fleetwood.