Bruno Fernandes questioned why Manchester United's players "can't do this every week" after they fought to earn a 2-2 draw with Premier League leaders Liverpool on Sunday.
Amad Diallo scored an 80th-minute equaliser to earn a point after Cody Gakpo and a Mohamed Salah penalty had turned the game around following Lisandro Martinez's opener.
United remain winless in their last 10 away games against Liverpool in all competitions (D5 L5), their longest-ever such run. However, they scored as many goals on Sunday as in their previous 10 such away games at Anfield beforehand combined (two).
They have not won in all competitions since beating Manchester City on December 15. However, a much-improved performance as they earned the draw at Anfield, with Harry Maguire also missing a glorious chance to win the game in the seventh minute of stoppage time.
Ruben Amorin expressed his frustrations with United's inconsistency under his leadership so far, with Fernandes echoing his sentiments.
Asked about the criticism United had faced in recent weeks, Fernandes told Sky Sports: "Criticised and fairly because the position in the table says it all, we lost too many points.
"We can't be happy with a draw because we need points more than they did.
"It was a really good result; we could have even won the game in the end, but it's a fair result.
"I'm pretty upset because if we show this at Anfield against Liverpool, who are first in the league and probably the outstanding team in the Premier League this season, why can't we do this every week?
"Finally, I did a proper performance overall and I think we need much more from ourselves to get something from this season."
United’s next match is in the FA Cup against Arsenal, who dealt Amorim his first defeat in charge of the Red Devils in early December.