Whites head coach Marcelo Bielsa made six changes to his team for Sunday’s third-round clash at Loftus Road, with an eye on Friday night’s return to Championship action at home to sixth-placed Derby County.
With several players already out injured, a youthful Leeds side with an average age of just 22 played, with the average age of United’s seven substitutes falling to just 19.
Leeds went behind to a 23rd-minute penalty converted by Aramide Oteh but equalised just two minutes later when 20-year-old Finn Aapo Halme cashed in on a goalkeeping error from Matt Ingram.
Both sides then had chances to bag a winner but Steve McClaren’s Rs booked their place in the fourth round when Jake Bidwell headed home a 75th-minute corner.
Leeds – who sit two points clear of second-placed Norwich City at the top of the Championship – can now focus solely on the league with just 20 games standing between the Whites and a potential long-awaited return to the Premier League.
But captain for the day Forshaw refused to belittle the importance of the FA Cup with the skipper admitting his side also wanted a run in the competition as an opportunity to offer the club’s youngsters valuable game time.
The midfielder also admitted there was “no hiding” from the fact that Leeds had now lost three games in a row with the 27-year-old determined to set the record straight against Derby.
Asked if it might be a blessing in disguise going out in the third round and avoiding extra games, Forshaw said: “I can understand why people would feel like that but as competitors and as players you just want to win games.
“You want to create that confidence and belief and we want to put it right as soon as possible.
“There is no hiding from the fact we have lost the last couple.
“I thought we had a decent performance, especially in the second half, creating chances like we do.
“Maybe on another day they go in and we are into the next round ourselves.
“It’s an important competition and it’s a chance for people who may not be playing as much to stake a claim and try and get in the manager’s thoughts a little bit more. You are always disappointed to lose a game.”
Leeds almost took the lead after just 28 seconds when Tyler Roberts unleashed a powerful volley that smacked against the post and whizzed across the goalline before hitting the opposite post and rolling clear.
Instead, it was the Rs who drew first blood with a 23rd-minute penalty awarded after left-back Leif Davis had sent Bidwell tumbling in the box.
Oteh smashed home the penalty but Leeds drew level just two minutes later when a long-range free-kick taken by Lewis Baker was spilled by Rs goalkeeper Ingram allowing Halme to convert from close range.
Leeds then had their chances in the second half but only a superb one-handed save from Peacock-Farrell kept out a powerful drive from Jordan Cousins which was tipped on to the post and wide for a corner.
But Peacock-Farrell was left picking the ball out of his net for a second time with 15 minutes remaining as Bidwell headed home what proved the winning goal.
The Rs then hit the post for the second time with four minutes remaining when a brilliant free-kick from Luke Freeman beat Peacock-Farrell but not the woodwork.
“It was a decent game,” said Forshaw. “We created a lot of chances as we do, we are just disappointed as we always are if you lose a game. It was a good chance for the young lads to show what they can do and I think they gave a good account of themselves.”
Leeds United: Peacock-Farrell, Shackleton, Halme (Pearce 45, Temenuzhkov 79), Ayling, Davis (Odour 87), Forshaw, Clarke, Baker, Roberts, Alioski, Harrison. Unused substitutes: Huffer, Diaz, Gotts, Stevens.
QPR: Ingram, Kakay, Furlong, Hall, Bidwell, Osayi-Samuel (Wszolek 86), Scowen, Cousins, Freeman, Eze (Smith 89), Oteh (Chair 83). Unused substitutes: Lumley, Manning, Baptiste, Chair, Smyth.
Referee: G Eltringham.