The Royals were on form in a fine 4-1 home win over Bristol City on Boxing Day to climb to within a point of the play-off places and McDermott is likely to stick with the same XI if he can.
Striker Shane Long took his tally to four goals in two games with a brace against City and will continue in attack alongside Noel Hunt with Jobi McAnuff and Jimmy Kebe on the wings.
However should McDermott decide to freshen up his front line for a second game in three days Simon Church, Hal Robson-Kanu and Michail Antonio could all come in.
Club captain Ivar Ingimarsson (hamstring) completed 90 minutes for the reserves earlier this month and the defender could be involved for the first time this season.
His Icelandic compatriot Brynjar Gunnarsson (knee) is also back in training but the defensive midfielder is not expected to start.
Source: PA
Source: PA