The Blades have been drawn away to Ipswich Town in the Emirates FA Cup third round.
The number 34 ball assigned to the Blades was second out of the famous velvet bag.
The draw was made on Monday evening at Slough Town's Arbour Park before their second round tie against Rochdale.
The third round will take place across the weekend of 5th-8th January 2018. Confirmed date, kick-off time and ticket news will follow in due course.
United beat Ipswich at Bramall Lane in October, with Chris Basham scoring the only goal.