The Yorkshire rivals face each other in a mouth-watering semi-final at a sold-out Doncaster Keepmoat Stadium.
Bookmakers have Hull – who won at Wembley for the first time in their long history last year – as slight favourites to progress even though Leeds are second in the Super League table, one place above them.
Furthermore, the Rhinos have won eight successive games against these opponents and claimed the famous cup in 2014 and 2015.
However, the odd-makers have probably taken into consideration just how hard Hull strived to end finally that annoying hoodoo and acknowledge it will now take something special to prise the trophy from their grasp.
McDermott has won the competition as a player – with Bradford Bulls at Murrayfield in 2000 – and is aiming to push on for a third success since taking over as coach at Headingley at the end of 2010. But he conceded: “They are a funny thing, Challenge Cup games. Maybe because it’s knockout. I don’t know.
“Maybe because it’s such a short and intense competition; it’s not like the Super League season where the Grand Final is the culmination of 30 league rounds and then the play-offs.
“This is such a short, intense competition. You just don’t get any second chances.
“So maybe because of that people always look gassed, especially in semi-finals.
“Everybody just looks tired and it doesn’t look like a normal game.
“People play a little bit differently; execution’s not the order of the day – sometimes it’s just possession and field position.
“So I think we’re ready for a different type of game. We’re ready for an energy-sapping type of game and I think the start in that is key. The first 10 or 15 minutes of any match are really important, but especially in the Challenge Cup.”
Leeds are appearing in a record-equalling 47th Challenge Cup semi-final, level with Wigan Warriors who face Salford Red Devils at Warrington tomorrow in the other last-four tie.
For all Rhinos hold sway over Hull in recent times, though, most recently with a 10-7 victory at Headingley a fortnight ago, there is no denying Lee Radford’s side are primed potentially to turn that around.
McDermott admitted: “It’s an interesting one; I think Hull have been very good this year and have shown enough this year that they are capable of being almost unplayable at times.
“They have a real physical team and carry the ball very strongly.
“And if they want to do it and decide to do it and things go well for them on game day, they become a really difficult team to beat.
“But then I say the same about us. We’ve been great this year. On occasions we’ve been very, very good and we’re really looking forward to it. We’re in good shape.”
Leeds are expected to be near full-strength with England second-row Brett Ferres hoping to prove his fitness in time after recent knee surgery while forward Jamie Jones-Buchanan is set for his 400th career appearance.
However, with England prop Scott Taylor marking his 200th career game, Hull are similarly strong especially if Albert Kelly, their electric Australian half-back, passes his own medical tests after a recent calf strain.
Crucially, too, they have their inspirational captain Gareth Ellis back in the fold after he played his first Super League game in three months last week following an irritating sternum injury.
It was the former Great Britain second-row who lifted the Cup at Wembley last August and he is desperate to get the chance to relive that moment.
“It’s a massive game and a great opportunity,” said Ellis, who was in the Leeds side that lost to Hull the previous time they won it in 2005 at Cardiff.
“Obviously we had the success last year and know how good it felt. To get the opportunity to push on and maybe do it again is massive for the club.
“Since I’ve been here (Ellis joined in 2013) consistency has always been an issue. (But) if we could get the result against Leeds it would be a massive step forward in achieving that.
“A lot of the boys felt the sadness of losing the Challenge Cup final in 2013 versus Wigan and to reverse that and win it finally in 2016, I think I know which side of the coin the boys want to be on.
“People still speak in the changing rooms about it to this day and there’s memories that live with us forever. But we want to do it again.”
Leeds will look to get captain Danny McGuire and Rob Burrow to Wembley one more time after they revealed this would be their last season in blue and amber.
Ellis, 36, played with both stellar halves in his time at Headingley and said: “They are legends of this era.
“They will be remembered forever – I’m good friends with both - and the real credit to them is how they’ve adapted their game.
“We know Leeds will use their recent announcements as an incentive and we have to be ready.”
Cup previews: Pages 6-7.