The game is likely to be on 28th or 29th August.
Northampton have visited Teesside four times in the past. The lat time was 11th September 2001 when Boro won 3-1 in the same competition. Boro have clocked two 1-0 league game victories.
The two teams first met on 12th January 1907 and Middlesbrough won 4-2.
The full draw is listed below, with the Premier League teams taking part in bold.
Birmingham v Hereford
Bristol City v Man City
Bristol Rovers v West Ham
Burnley v Oldham
Cardiff v Leyton Orient
Carlisle v Coventry
Charlton v Stockport
Derby v Blackpool
Luton v Sunderland
Middlesbrough v Northampton
MK Dons v Sheff Utd
Newcastle v Barnsley
Nottm For v Leicester
Peterborough v West Brom
Plymouth v Doncaster
Portsmouth v Leeds
Rochdale v Norwich
Sheff Wed v Hartlepool
Shrewsbury v Fulham
Southend v Watford
Swansea v Reading
Wigan v Hull
Wolves v Morecambe
Wrexham v Aston Villa