The 24-year-old is available on a free transfer following his release from the Gills and Brown admits he is not the only one interested in the former Wigan trainee.
"Lewis has been in for us to have a look at him but there is also another club who want him," Brown told the Southend Echo.
"We're after a creative type of midfield player and whether or not Lewis fits that bill I don't know.
"When he was with us we were doing running and fitness tests and he certainly impressed where that was concerned.
"But I would like to have another look at him when we're doing more ball work to try and get him over the line."
Montrose spent the end of last season on loan at Oxford after falling out of favour at Gillingham. He has previously played for Wycombe and has had loan spells at Rochdale, Cheltenham and Chesterfield.