Games will take place on the week commencing November 21.
And United will also find out who they will face when the FA Cup gets underway.
The draw, which will be shown live on BBC1 and Sky, will be made at 5.10pm by legendary players Sir Tom Finney and Roy Bentley.
Scunthorpe will be ball number 37, and could play any club from League One or Two - or one of 32 qualifiers from non-league, with the final qualifying round being played on Saturday.
FA Cup round one numbers in full:
1 AFC Bournemouth; 2 Barnet; 3 Barnsley; 4 Blackpool; 5 Boston; 6 Bradford; 7 Brentford; 8 Bristol City; 9 Bristol Rovers; 10 Bury; 11 Carlise; 12 Cheltenham; 13 Chester; 14 Chesterfield; 15 Colchester; 16 Darlington; 17 Doncaster; 18 Gillingham; 19 Grimsby; 20 Hartlepool; 21 Huddersfield; 22 Leyton Orient; 23 Lincoln; 24 Macclesfield; 25 Mansfield; 26 MK Dons; 27 Northampton; 28 Nottingham Forest; 29 Notts County; 30 Oldham; 31 Oxford; 32 Peterborough; 33 Port Vale; 34 Rochdale;35 Rotherham; 36 Rushden; 37 Scunthorpe; 38 Shrewsbury; 39 Southend; 40 Stockport; 41 Swansea; 42 Swindon; 43 Torquay; 44 Tranmere; 45 Walsall; 46 Wrexham; 47 Wycombe; 48 Yeovil; 49 Harrogate Town or Scarborough; 50 Tamworth or Altrincham; 51 Southport or Kidderminster; 52 Hucknall or Burscouth; 53 Blyth Spartons or Chasetown; 54 Northich Victoria or Barrow; 55 Gainsborough Trinity or York City; 56 Ossett Town or Leamington; 57 Accrington Stanley or Worcester City; 58 Hednesford Town or Vauxhall Motors; 59 Halifax or Farsley Celtic; 60 Burton Albion or Leek Town; 61 Hereford or Alfreton; 62 Bromsgrove or Morecambe; 63 Crawley or Braintree; 64 Canvey Island or Burnham; 65 Kettering or Gravesend; 66 Dorchester or Welling; 67 Bromley or Aldershot; 68 Histon or Hayes; 69 Grays Athletic or Cray Wanderers; 70 Nuneaton or Tiverton; 71 Exeter or Stevenage Borough; 72 Woking or Thurrock; 73 Basingstoke or Chippenham; 74 Cambridge City or Lewes; 75 Merthy Tydfil or Farnborough; 76 Aylesbury United or Folkestone Invincta; 77 Forest Green or Dagenham; 78 Ramsgate or Cirencester; 79 Weymouth or Cambridge United; 80 Bishops Cleeve or Eastbourne Borough.
Check back to Iron-Bru.net on Saturday for the full draws from both competitions.