Daniel Farke was left fuming after Leeds United had a goal disallowed in their play-off semi-final first leg at Norwich on Sunday.
The game at Carrow Road ultimately ended 0-0, with both sides failing to seriously trouble the opposition goalkeeper as the teams combined for just 0.8 xG (expected goals).
It leaves the tie finely poised ahead of Thursday's second leg at Elland Road, but despite his side heading back to home turf with a clean sheet and level in the tie, Farke was left frustrated by a first-half incident which saw Junior Firpo put the ball in the net following a mix-up between Shane Duffy and Angus Gunn, only for the offside flag to be raised.
Farke believes the goal should have stood and bemoaned decisions that have gone against his side this season, telling reporters: "I can just recommend everyone should have a look on the scouting feed, it's not offside.
"I'm annoyed. I have to make sure I'm not too much in a rage. Small details make a difference, if you go in the lead it changes the picture. In the end, everyone speaks about Wembley, a £100m game. At this level, all the decisions have to be spot on.
"Perhaps [the linesman] was a bit scared the whole stadium is moaning if he doesn’t give offside. No, in doubt you give it in favour to the attacker. It's definitely not offside.
"If you want to be in charge of such a game you have to be spot on. I have 12 letters apologising already this season. We have to make sure we find a way even though this crucial decision went against us."
Despite his annoyance at the disallowed goal, Farke remained content with his side's display as they bounced back from a challenging end to the regular season with a clean sheet.
"When you play a play-off semi-final with two legs, an away draw and a clean sheet at a difficult ground is always a good and solid result," Farke continued.
"The last games in the regular season were not great, we conceded too many goals and in away games especially. We wanted to be rock solid today against the ball.
"Overall I have to say I'm pretty happy. We have a massive game on Thursday evening. It's just half-time."
Though David Wagner's Norwich side now face the daunting task of a trip to Elland Road, the Canaries boss feels his players are capable of overcoming the raucous home atmosphere to reach the final at Wembley.
Wagner is also looking to draw upon his experiences during his time at Huddersfield, where his Terriers team beat Sheffield Wednesday on penalties at Hillsborough before going on to win another shoot-out at Wembley against Reading to clinch Premier League promotion.
"Every single second we are in the game at Elland Road, it is a minute in our favour," Wagner stated at his post-match news conference.
"I said beforehand we are the underdogs. The expectation is on Leeds. We know this.
"I have experienced being the away team in the play-offs."
Norwich captain Kenny McLean echoed his manager's belief that the Canaries can go and win at Elland Road, telling Sky Sports: "We know how good Leeds can be at home and they'll fancy their chances, but we’re a very good team as well."