The Bees were beaten 6-1 by Midland League Division One Atherstone Town at the HTFC Community Ground on Saturday, after having keeper Daniel Farrell dismissed in the 21st minute.
Manager Spencer said there was ‘no blame’ attributed to Farrell, who was sent off for making a reaction stop inches outside his box.
However, he did feel that his keeper’s early bath contributed to the scoreline.
“The day didn’t play out as we wanted it to,” he told The Mail.
“The game itself got off to the worst possible start with our keeper being sent off.
“Atherstone are a strong side and I think, being brutally honest, they would have still progressed.”
Spencer felt his squad - who scored a 78th-minute consolation through Barnes Gladman - didn’t rise to the occasion.
But he believes the experience will only make them stronger.
“I think maybe the occasion got the better of the players,” he added.
“We never really implemented what we’re about, which was the disappointing thing for me.
“But it was a big day for the club in terms of having almost 350 people in the ground.
“And if the players learn from the experience and maybe we can get into a similar position again they will put in a better performance.”