Brown saw his side's run without a league win reach a dozen matches with a goalless draw on Friday night and the result kept the visitors just outside the play-off zone.
Brown's assistant Dave Penney said: "Phil has been under the weather for a couple of days with a flu-like thing and was communicating with me via his mobile phone.
"We feel we had the better of the game, particularly in the second half, but couldn't take one of the opportunities that came our way.
"I can't recall our goalkeeper making many saves and if we had won 1-0 it would have been the perfect away performance.
"As it is we are still playing catch-up on the teams above us.
"But there was plenty there to build on and we are still right in the play-off battle."
Southend substitute Jamar Loza mistimed his header from a good chance late on, while for the the home side John-Joe O'Toole headed straight at goalkeeper Daniel Bentley in the 83rd minute.
- Sports & Recreation
- Dave Penney