Ralf Rangnick cited a lack of aggression as his Manchester United side were held to a draw by Premier League strugglers Burnley on Tuesday night.
United dominated the first half but only had Paul Pogba's fine finish to show for it at the break, with a Raphael Varane header ruled out for offside and a Josh Brownhill own goal chalked off for a foul in the build-up.
Burnley came flying out of the traps at the start of the second period, catching their visitors cold and equalising within two minutes through Jay Rodriguez. Despite having 43 minutes to score Man Utd were unable to find the winner. The result follows the disappointing FA Cup defeat to Middlesbrough on Friday.
Speaking after the match, interim manager Rangnick said: "At the end, it is a frustrating evening for us because we should have won that game easily after the first half and even the last 25 minutes we had full control and dominated the game but were not decisive enough as we were in the first half.
"In the end, it was a little bit a case of luck with Raphael Varane, the header by Cristiano, Harry Maguire, but in the end one point for a performance like this is just not enough."
Speaking about the disallowed own goal, Rangnick added: "In particular, the second one that was disallowed, I watched it right now in the locker room. The linesman flagged for a foul but he flagged 10 seconds after that incident. This was a very soft decision, I must say.
"But again we played an excellent first half, I thought. We totally dominated the game, scored three goals but two were disallowed.
"Then in the second half, for the first 10 to 15 minutes, we were just not aggressive enough. It was clear they would come out after the break in a more aggressive way to play but we were not aggressive in those 15 minutes. We gave away the goal.
"We had a very good counter-attacking situation 30 seconds before we conceded the goal and the way that we allowed them to score, we did not defend the whole situation well."