Mark Warburton insists a Hampden hangover was not behind his side's Easter Road defeat to Hibernian.
The recently-crowned Ladbrokes Championship winners arrived in Edinburgh still floating on the high of Sunday's victory over Old Firm rivals Celtic.
The Ibrox men had to battle through 120 minutes of tense action at the national stadium before finally clinching their place in the William Hill Scottish Cup final on penalties.
But the spark that produced the shock victory over Ronny Deila's men was missing in Leith as they slumped to a 3-2 defeat to the side they will face in the May 21 showpiece.
Hibs took the lead after just five minutes when Jason Cummings pounced on a loose James Tavernier throw-in, and keeper Wes Foderingham gifted the hosts a second as he clawed an Anthony Stokes cross into his own net.
Easter Road keeper Mark Oxley - restored to Alan Stubbs' line-up despite Conrad Logan's Hampden heroics in their semi-final win over Dundee United on Saturday - was also to blame as Jason Holt prodded one back for Gers but Norwegian full-back Niklas Gunnarsson smashed Hibs back in charge, rendering Barrie McKay's late wonder-strike meaningless.
Warburton insisted fatigue was not to blame for his side's loss.
He said: "No not at all, Sunday was totally irrelevant. That is next year if we win the cup and have the Europa League. You saw the fitness levels, you saw Barrie McKay running back 40 yards in the 93rd minute.
"We were physically fine, mentally fine. It is disappointing to start the game well and then give away a soft, soft goal. That can't happen. The third goal allows them to sit deep and they had 10 men behind the ball so it is hard to break down.
"We got a great strike from Baz, who again produced an outstanding level of performance. We should have had more chances with all the possession we had. To come here and have 70 per cent of the ball tells you all you need to know."
Hibs' victory means their hopes of catching second-placed Falkirk and sparing themselves an extra two games in the play-off remain intact.
They sit three points behind Peter Houston's team with a game in hand.
But Stubbs does not believe his side will now have the whip hand heading into the cup final.
"This result has no relevance to the cup final at all," he said. "That's not for another month. Over the course of the season you've seen two teams play each other four times and we've both won the games at home.
"But it helps us in the race for second. We still have three games to go and it keeps it alive. We've kept up our part of the bargain with four to go before tonight.
"We want to pick up maximum points."
Hibernian: Oxley, Gunnarsson, McGregor, Hanlon, Gray, Fyvie, Bartley, McGinn, Stevenson, Stokes (Dagnall 89), Cummings (Keatings 77).
Goals: Cummings 5, Stokes 18, Gunnarsson 58.
Rangers: Foderingham, Tavernier, Kiernan, Danny Wilson, Wallace, Ball (Zelalem 61), O'Halloran (King 61), Halliday, Holt, McKay, Miller (Shiels 77).
Goals: Holt 41,McKay 85.