All three picked up hamstring injuries in last weekend's 2-2 draw with Oldham and are unlikely to figure again this season.
Manager Steve Tilson is considering handing a full debut to 18-year-old striker Harry Crawford, while Stuart O'Keefe and Jean-Yves M'voto are also set to start.
United remain without long-term absentees Damian Scannell (foot) and Scott Spencer (ankle) while full-back Scott Malone has been recalled by Wolves, bringing to an end his six-month loan spell at the club.
The draw with the Latics sent Southend to relegation and they now have only pride to play for in their remaining two fixtures.
