"It looks as though we are going to miss Justin, which is a shame because the side that beat Exeter would have been my side to play Southend. They picked themselves by that display."
Mohan came off the bench to replace him and is expected to stay in the side at Southend. The 31-year-old took Whittle's place at Kidderminster when he was suspended three weeks ago, but that was his first start since early November.
However, Brian Little says that he has no worries about playing him.
"Nicky's taken some stick this season, but he's not been playing in his best position on the right side of the central defence.
"We've had to use him on the left, which is not ideal for him. Now, with Matthew Wicks coming here, it gives him a chance to play where he is happiest."
Little said that recent acquisition Wicks could be the backbone of City's side for years to come.
"Matthew has the potential to play a lot higher, but he's very young.
"It's good to see a left-footed centre back that has good pace for a big man, and we've given him the stage here, and hopefully he will go on and prove to be a very good signing for us."
Theo Whitmore has recovered from a calf injury but will have to be content with a place on the bench again with Greaves and Johnsson keeping him out of the side.
Mike Edwards, Little's man of the match on Saturday, is thought to have a very slight groin strain but should play. Ian Goodison is still out. Ben Petty, Jason Van Blerk and Gary Bradshaw have been called up to the squad travelling to Roots Hall.
Expected line-up (4-4-2): Musselwhite; Edwards, Mohan, Wicks, Holt; Williams, Johnsson, Greaves, Beresford; Alexander, Dudfield.
Subs from: Glennon, Van Blerk, Petty, Matthews, Sneekes, Whitmore, Rowe, Bradshaw.