Yorkshire rivals Doncaster Rovers visited Elland Road and left with the points to consign Leeds to their fifth defeat in six games.
On the pitch, McDermott has no new injury concerns for Tuesday's visit of the Addicks, who have won two of their last four games to climb out of the bottom three.
Jose Riga has overseen those recent victories and Charlton still have at least two games in-hand on all other sides around them.
The South London side were comprehensively beaten by Derby County on Saturday though and Riga might opt to shake up his starting lineup when they travel North to Leeds.
Possible starting lineups
Leeds: Butland; Byram, Lees, Pearce, Warnock; Mowatt, Austin, Murphy, Stewart; McCormack, Smith
Charlton: Hamer; Wilson, Morrison, Wood, Wiggins; Poyet, Jackson; Cousins, Ghoochannejhad, Sordell; Obika
Sports Mole says: 2-0