Head Coach Nelson Jardim admitted his side were well below par after falling to a 4-0 defeat against Swindon Town on Saturday afternoon.
Four first-half goals from Kabongo Tshimanaga, Paul Glatzel, Joel Cotterill and an own goal from Matt Baker inspired the Robins to their first win of the campaign.
“It was a very tough afternoon and I apologise to the fans, they deserve much more,” said the Exiles boss.
“The first half was alarming and I apologise to the fans. Too many of us were off the pace and we have to make sure we come back with more energy, desire, aggression.
“We have to understand that we can only play if we get the basics right. You have to compete, especially when you are away in front of a big crowd. Don’t do that and you will struggle.
“There were too many changes [because of injuries and suspensions], I get that, but that is what the squad is there for. We have options and that is not an excuse for not competing as we should.
“I take the full responsibility for that, I have to protect the players and now it’s time to stick together and make sure we address it on Monday to get back on track.
“We just have to make sure we are at it next game so that the fans feel proud of us again.”