"It wasn't Glenn's fault because he trains us well," insists Seb, "and the problem doesn't come from him, it comes from us.
"It is only the players' fault. It is the players that play and we were well prepared by the coaching team.
"What we have to do is really work because when you see teams like Birmingham, West Brom and Charlton come and win at our place, it is unacceptable.
"It is incomprehensible, and it is not even footballing teams that are coming to Upton Park, but teams putting up 10 at the back.
"We are not managing to overcome teams like that and I find that disappointing."
Even now, Seb is struggling to explain what went wrong against Birmingham, and he adds: "We were very disappointed - and angry on Saturday," he says.
"The team was very bad, nothing is going forwards at the moment and it is very difficult.
"I don't know what happened, after the goal from Gary's error it wasn't the same match.
"We lost confidence, and I, personally, knew it would be difficult to come back after that.
"No one was happy, not the fans and not the players - and that was the worst match I have played in here.
"I don't know what is going on. The fans are waiting a little bit for us to produce but they are disappointed - which is normal.
"We need everyone at the moment and we have to dig deep."
The Hammers are now on the road for the games at Sunderland and Fulham but in the back of Seb's mind is the need to get it right in east London.
"Now we have two matches away which are very important and we are going there to win. I am confident that we can do that and we have the mentality to do so," he says.
"We are nervous at home because we know we can't make mistakes in front of the supporters who are very angry at the moment.
"That goes without saying and it is very understandable - we have to react and start winning at home very soon to rid ourselves of this curse."
And he admits that no rhetoric was needed in the dressing room after the defeat - because the players knew they had not performed.
"Glenn tried to find the right words at the right moment but it was difficult," he says.