Brown rues his side's defensive display at Scunthorpe as Blues fail to progress.
“It wasn't to be and we're disappointed. We conceded two very sloppy goals which is unlike us and we're disappointed.”
Southend United boss was left frustrated by his side's defensive performance as the Blues bowed out of the Emirates FA Cup first round following a narrow 2-1 defeat to Scunthorpe United.
A Paddy Madden brace sandwiched Ryan Leonard's good strike, but for the second season in succession, the Blues are out at round one.
“It was the same as last week; we didn't defend the set pieces correctly and we got deeper as the game went on,” the boss reflected.
“Maybe it's time for a personnel change. How many opportunities do we create? We don't get on the end of crosses, we don't make the goalkeeper work.
“I've stuck with my centre halves, the back four and the goalkeeper, and, like I say, maybe it's time for a personnel change.
“Joe Pigott got in good areas and Myles Weston was a thorn in their backside as well.
“It all changed when [Darius] Henderson came on. I don't ask my defenders to change from their duties whether it be a big striker or any striker.
“It's really disappointing to go out of the competition.”
David Worrall came on early in the game after Stephen McLaughlin picked up an injury, and Brown found a positive in Worrall's performance at Glanford Park.
“Dave Worrall came on and grabbed everyone's attention and was a constant thorn in their side after Stephen McLaughlin went off injured. Dave's earned his shirt.”