Leeds were without centre Liam Sutcliffe and forwards Brad Singleton, Carl Ablett and Mitch Garbutt due to injury, along with suspended front-row Anthony Mullally.
To make matters worse, full-back Jack Walker and centre Kallum Watkins sustained knee injuries, prop Nathaniel Peteru damaged a biceps and hooker Matt Parcell suffered a shoulder injury, though lack of numbers meant he had to go back on.
McDermott described parts of Leeds’ performance as “soft”, but said the injury list made it “hard to be extremely critical of my group”. He insisted: “You might argue, if you are going to lose you should only be losing by a couple of points and you should still be in the contest.
“I agree. That has been happening, we have been losing or winning by a couple of points and I think today it just caught up with us. I thought we looked tired. We have some important people missing and when that dynamic changes and I get my front-rowers back and get them back consistently, I might be a bit more critical and examine a loss a bit more than I’m going to do.”
In contrast, Castleford coach Daryl Powell believes things are looking up.
He said: “Once we got a grip of the game we did some excellent things.
“Our left-side was particularly creative in the first half and our pack was immense.”