Lee Barnard was devastated after missing the first penalty of his career on Friday night against Leeds United.
Barnard, who has scored seven times this season, saw his penalty impressively pushed around the right post by Shane Higgs in the second half at Roots Hall.
And Blues top scorer is still kicking himself for failing to score what could have been a winner against the League One pacesetters.
"I really can't remember the last time I missed a penalty and I'm just absolutely gutted," said Barnard.
"I never even missed in the reserves at Tottenham so I was confident of scoring and I'm so disappointed it didn't go in.
"The keeper has a good reputation and it was a decent save but I should have scored and I know that."
Despite failing to convert it hasn't put the 25-year-old off putting himself forward in the future.
"I will step up again next time," he confirmed.
"Missing a penalty is a horrible feeling and one I don't want to experience again. The important thing is how you react and I'm determined to make amends.
"I'm confident of scoring my next penalty and hopefully I can bounce back by scoring on Saturday against Brighton."
Blues also head into that game in positive spirits after producing a determined performance against a Leeds side who have yet to be beaten this season.
"The positive thing is that we've played well again," said Barnard.
"Leeds are a strong team and they had won every game before playing us.
"If we play like that against Brighton then we will have a great chance of winning."