Daniels has a good chance of returning for the trip to the Withdean Stadium after overcoming the back injury which kept him out of last weekend's 2-2 draw with Walsall.
But Williams will be without Luke Summerfield, who has gone back to parent club Plymouth after his loan deal expired. Adam Chambers will be hoping to take his place in central midfield.
Orient have no injuries or suspensions to contend with ahead of the clash with their fellow strugglers.
The match kicks off at 1pm.