However, the boss does feel that it is a positive that the team managed a win when performing below par.
"We weren't at our best today at all and, you've got to be honest, I felt West Brom played very well and Gary Megson should be proud of the way they played," said Glenn.
"The good sign for us is that we haven't played particularly well and we won.
"We were never really secure, never playing well and if they'd have had their finishing boots on we might have found ourselves behind.
"It's an honest assessment and the lads know they haven't played well enough."
Glenn offered an honest assessment of the team's display in the 3-1 win over West Brom and admitted the performance was not up to scratch.