The Scottish defender, who only joined the Shrimpers on non-contract terms earlier this month, broke a toe during last Saturday's 1-0 defeat at Bristol Rovers - in what was only his third appearance for the League Two club.
It is hoped Dailly could be fit for Southend's final match of the regular season and any possible involvement in the play-offs should they be unable to clinch a top-three finish.
Elsewhere, influential centre-back Mark Phillips hopes to be given the green light to feature having been forced off against Rovers following a nasty collision of heads and a subsequent bout of concussion.
Liam Dickinson (ankle) and JP Kalala (knee) have both been ruled out for the rest of the season.
Freddy Eastwood is in line for his first appearance at Roots Hall since returning to the Essex club on loan from Coventry last week, while winger Bilel Mohsni also runs out on home soil for the first time since being given a reprieve by Southend following his indiscipline at Morecambe last month.