Brown is resigned to losing his star pair
Goalkeeper Daniel Bentley and midfielder Jack Payne are both out of contract at Roots Hall and have been linked with a host of clubs - notably Rangers and Wolverhampton Wanderers, respectively.
Both players came through the Essex side's ranks and, as they are both under 24, will net the Shrimpers compensation when they eventually fly the nest.
Brown showers Bentley after Southend's League Two promotion
Discussing Southend's transfer plans, Brown told the Alan Brazil Sports Breakfast show: "One or two we're losing in terms of transfers: Dan Bentley's possibly going to Brentford, Jack Payne's possibly going to Huddersfield."
In terms of incomings, the 57-year-old added: "I have (got business to do). I've go three or four transfers on the go - possibly coming in."
According to a report in the Daily Mail, one of those could be Rangers striker Nicky Clark, who has also been linked with Barnsley, Bury and Peterborough United in recent weeks.
Clark scored 24 goals for the Light Blues
The 25-year-old is leaving Ibrox this summer, having helped them to two promotions in three seasons.
Southend finished 15th in League One last term - as many points off the play-offs - prompting a clear out at Roots Hall.
Bentley, 22, and Payne, 21, were offered new deals alongside winger David Worrall, but the trio look set to join the Shrimpers' exodus.
Payne scored nine goals from midfield last term