Bentley is regarded as one of the best young keepers around after earning rave reviews for his performances at Roots Hall.
The 6ft 4in goalkeeper kept 19 clean sheets for Southend last season and has been tipped to break into the England Under-21 set-up.
Bentley has made 69 appearances for Southend since breaking into the first team and a host of clubs from higher up the football pyramid have been keeping tabs on his progress.
A mystery Premier League club tested Southend's resolve to hang onto Bentley on transfer deadline day and Brown was delighted to keep hold of the athletic shot-stopper.
"We had what I would call a sizeable offer from a Premier League club for Daniel Bentley on transfer deadline day and we turned it down,” Brown told the Southend Echo.
"We didn’t feel the deal was right for us or Daniel at this stage and I’m delighted that he’s still with us."