The Dubliner trapped a nerve during Tuesday night’s 2-0 Carling Cup win over Port Vale at Glanford Park. He has had an x-ray on his neck to check for bone and shoulder damage.
United cannot recall Josh Lillis, the club’s backup keeper, from a loan spell at Grimsby Town until next week so will call on third choice Sam Slocombe if Murphy is not ready for the weekend.
Slocombe, signed from local non-league side Bottesford Town last season, made his first appearance in an Iron shirt on Tuesday night when he replaced the injured Murphy.
If Slocombe is keeping goal for the Iron then Kevin Pressman, United’s goalkeeping coach, is likely to be named on the bench to provide cover.
United said on Wednesday that there were around 1,750 tickets left for Saturday’s game, which kicks-off at 12noon on the advice of Humberside Police.
There are 1,500 spaces on the Doncaster Road terrace, less than 200 in the Scunthorpe Telegraph Stand and less than 50 in the Grove Wharf Stand.