Dimitar Berbatov slammed the Manchester United defence following the Reds' 2-1 defeat by Istanbul Basaksehir in the Champions League.
Ole Gunnar Solskjaer's side lost their second successive game in succession Wednesday as they feel 2-0 behind inside 40 minutes.
Former Chelsea striker Demba Ba opened the scoring for Basaksehir on 13 minutes, following a United corner where Solskjaer's side had no-one back to mark the Senegalese forward, who ran through and slotted his finish past Dean Henderson.
Things got worse for United 27 minutes later, when Edin Visca took advantage of more poor defending from the visitors.
Despite Anthony Martial getting one back for the away side just three minutes after Visca's strike, United had just one shot on target after their only goal of the game.
Speaking to Betfair, Berbatov said: "The performances of Manchester United players last night weren't what they should be, it was very bad. I never really know what to say about these performances, because there's no explanation.
"One week, 5-0 Leipzig, brilliant, next week, this. It makes no sense. It's why last week I said we shouldn't get ahead of ourselves, and why consistency is so important.
"The first goal especially, I can't even describe how bad that was. Demba Ba isn't Usain Bolt, and they still couldn't catch him. It was awful to watch.
"Simple things like positioning, and knowing who is back and who is not, players should know this. I've seen more than once now these guys not covering each other, simple things.
"They aren't one-off events, and they've made an impression on me. It was staggering to see how they left Demba Ba alone in that position, and the quality United have, it's terrible that they did it.
"I don't know who played the pass to Ba, but he never had an easier pass, or Ba an easier goal, in their lives.
"It was a mistake you'd see in a kids game. I could use stronger words to describe how bad this is, but everyone already knows this."
