Inconsistency has once again plagued the Magpies, with Alan Pardew's side unable to string together a run of positive results.
They have tumbled to 16th in the Premier League standings as a result, with back-to-back defeats dealing another blow to fragile confidence.
Anita feels it is time the players started to deliver on their potential, with concern starting to mount on Tyneside.
He feels added importance has been placed on Newcastle's next fixture and hopes they can offer a positive response to Monday's frustrating showing in a 3-2 defeat at Everton.
The Dutch midfielder said: "The table looks worrying now, I admit. It's a must-win game.
"It's like a Champions League game for us because it's so important. We must give it our all because you can't underestimate anyone in this division.
"We must recover and show the real Newcastle, the team of the second half at Everton - not the first half. We want to win and to do that, we must improve."