Ralf Rangnick was surprised by the linesman's decision to disallow a goal in Manchester United's draw with Burnley.
United were 1-0 up when Paul Pogba was adjudged to have impeded Erik Pieters just before Marcus Rashford's cross was bundled into his own net by Josh Brownhill.
Although Pogba was involved in a physical duel with Pieters, the midfielder was still disgruntled by the decision and remonstrated with the official at half-time.
United had a goal disallowed at 0-0 because Harry Maguire was deemed to have been interfering with play from an offside position when Raphael Varane nodded in. Maguire insisted 'it was definitely not a foul'.
"I think we played a fantastic first-half, couldn't have played any better," Rangnick told the BBC. "We scored three goals, the second that was disallowed, I cannot understand. It was a very, very soft decision by the linesman. He flagged the foul five or six seconds after it took place.
"It really surprised me he flagged when the ball was in the net. Had he really seen the foul? The first I can understand why it was disallowed, it was a hard one, but the second I cannot understand.
"We scored three goals! That is different to Friday (against Middlesbrough). The second one that was disallowed, the linesman flagged foul but 10 seconds after that incident. This was a very soft decision I must say."
Despite his dissatisfaction with the officiating, Rangnick conceded United should have won the game 'easily' after dominating another first-half only to go in at the pause just 1-0 up.
Burnley equalised within two minutes of the restart through Jay Rodriguez as United drew their second successive game 1-1 to drop down to fifth in the Premier League table.
"It was 1-0 at half-time, we knew they would come out in the second-half in a more aggressive way and the only thing I can complain the team about was we were not aggressive enough in the first 20 minutes of the second half," Rangnick added.
"If you look into the whole game we dominated for most of it. Winning one point is not enough and frustrating again.
"[In the second half] We were playing tiki taka football in our own half and not direct enough. We had the counter-attack but gave the ball away too easily in their box."
