He said: "The first half performance was way below the standards we've set ourselves this year and we deservedly came in losing. We put on a much better second half, but we've come away with nothing and it's very disappointing."
Sean Thornton and Scott McGleish were replaced in the 53rd minute of the clash against Les Parry's men by James Scowcroft and Jonathan Tehoue and both will be vying for a starting berth following the loss.
Winger Jimmy Smith earned a recall to Williams' side at the weekend after Nicky Adams was recalled to Leicester last week and he should retain his place in the starting XI.
Williams has no fresh injury or suspension worries to contend with as he tries to get his side's play-off ambitions back on track.