Gary Megson rued the fact that Wednesday failed to turn their early dominance into a crucial first goal against Chesterfield on Saturday.
The Owls bossed the opening 45 minutes at the B2net Stadium but fell short in front of goal and the Spireites went on to win the game via a second half penalty.
Megson said: "I thought we made a really positive start to the game but we didn't score. We always stress the importance of scoring the first goal and Chesterfield scored it.
"The penalty was soft, not in the way it was given, but the way we defended it. The tackle couldn't have been made and it has cost us the game.
"But I thought we dominated the game for 45 minutes and when you do dominate as much as you have done, especially away from home, it's so important that you score the first goal.
"In the second half we didn't penetrate them as much as we had been doing and I think Jermaine Johnson going off had a lot to do with that because he certainly gives you that as an individual.
"We may have won this stat, this stat and the other stat but there are two stats that really count and they are putting the ball in one net and keeping it out of the other.
"From our point of view, we need to regroup and push on."
Megson revealed that dangerman Johnson was withdrawn with a knee injury and the prognosis will follow in due course.
He said: "It was a huge blow to lose JJ because he is right on top of his game and playing as consistently as I have seen him.
"It looks like it could be a medial knee ligament but hopefully it might only be a knock, we will find out when we have taken a proper look at him."