The Royals' success over recent years, which saw them claim the Championship title in 2011/12, has been built on consistency and stability.
McDermott is, however, prepared to shuffle his pack if he feels a change in personnel would benefit the club and bring about a reversal in fortune.
He saw the usually reliable Kaspars Gorkss make two costly errors in a 3-2 defeat at Wigan on Saturday and has hinted that the centre-half, who has been an ever-present so far this term, may be axed for Tuesday's trip to fellow strugglers Aston Villa.
McDermott said: "No-one in this team is undroppable.
"Kaspars has been a warrior for me. He did well in the Championship and he is part of four centre-backs. He is up for selection.
"I'd not talk about any player's performance. That would not be right."