26-year-old Williams made his Town debut last night against Brigg and whilst not impressing the majority of the Town fans, he has impressed Slade.
With Alan Fettis returning to Hull - later moving on to Macclesfield - and Aidan Davison leaving for Colchester, Town went into pre-season with only rookie Paul Fraser registered as a goalkeeper.
Slade has moved to sort that with the signing of the former Hartlepool man but could well look to bring another 'keeper in before the season starts.