The Rhinos, who have won the Grand Final for the last two years, suffered their first play-off defeat since 2010 when they went down 40-20 to Warrington at the Halliwell Jones Stadium on Saturday.
However, they get a second bite of the cherry after finishing in the top four and will take on St Helens at Headingley on Friday for a place in the semi-finals.
With a host of senior players still working their way back from lengthy injury lay-offs, McDermott is not unhappy about having to play again this week.
"I've been saying for a few weeks that we've some fellas that need to catch up on game time," he said. "We wanted to win and have next weekend off but at the same time we'll look for the positives.
"And, should we get through to the following week, we will have a few more men with a bit more game time."
Leeds were back to full strength with the return from suspension of prop Ryan Bailey and they opened up a 10-6 lead thanks to tries in the first quarter from England centre Kallum Watkins and skipper Kevin Sinfield.
However, they were blown away by the efforts of England second rower Ben Westwood, who scored two tries in each half, and although full-back Zak Hardaker touched down for two late tries, the champions finished a well-beaten side.
"Confidence will be an issue," McDermott said. "We will have to address that.
"We got done by a good team. We've got to turn things around in training next week and develop a bit more of a steely attitude towards the next game."
Warrington's victory earned themselves a week off and, after league leaders Huddersfield lost to Wigan, it also gives them the right to select their semi-final opponents under the ClubCall system so despised by their coach Tony Smith.
For the last two years Leeds were chosen under ClubCall after being perceived to be the weaker side and went on to turn the tables on their hosts.
Smith says he will be a reluctant participant when the ClubCall is held next Sunday.
"I think it's crazy," he said. "It makes it very, very difficult to explain our finals system.
"It's already complex and then to say we don't really know who we're going to play and it's up to somebody after all the games are played in the second week really confuses the general public.
"For what it gains, I don't think it actually brings a whole lot to the table. And I don't want to do anything to motivate anybody else. How well has it worked so far?
"I think the team that gets picked has got a pretty good record of upsetting the team that picked them.
"At this time of the year you don't want to give any more motivation. If they make me go and participate, I'll happily toss a coin."
St Helens booked their trip to Leeds with a 46-10 win over Hull KR in which winger Adam Swift scored a hat-trick of tries and coach Nathan Brown believes his team can go there with optimism.
"We have some confidence now," Brown said. "We have a big task against Leeds but we should go there thinking we can do okay.
"The guys want to do well and it will be a really good game. We want to stay alive and give ourselves a good shot at Old Trafford."
The first preliminary semi-final will take place on Thursday when Huddersfield meet Hull at the John Smith's Stadium hoping to avenge a 46-10 rout in last year's play-offs.