The EFL had to move the fixture, originally set for Saturday, April 25, as Saints will be playing at Wembley in the last four of the FA Cup that weekend.
Tonda Eckert’s play-off chasing side will do battle with an in-form Lancashire outfit, who sit 19th in the table and are trying to preserve their league status.
Saints have said that ticket purchasers who cannot attend the rearranged match must contact the ticket office in writing by 5pm on Wednesday, April 8.
The clash was initially selected for Sky Sports broadcasting, and it will still be televised with full studio coverage on the rescheduled date.
Saints will play two games a week every week until the end of the season. They have seven Championship fixtures and an FA Cup match to fulfil.
They visit sixth-place play-off rivals Wrexham up next on Tuesday, April 7, before hosting Derby on Saturday and Blackburn just three days later.
Then it is a trip to Swansea and home ties with Bristol City and Ipswich Town before concluding the league season at Preston on Saturday, May 2.
Saints fixture schedule
Tuesday, April 7 – Wrexham vs Saints (8pm)
Saturday, April 11 – Saints vs Derby County (3pm)
Tuesday, April 14 – Saints vs Blackburn Rovers (8pm)
Saturday, April 18 – Swansea City vs Saints (3pm)
Tuesday, April 21 – Saints vs Bristol City (7.45pm)
Saturday, April 25 or Sunday, April 26 – FA Cup semi-final, Wembley.
Tuesday, April 28 – Saints vs Ipswich Town (7.45pm)
Saturday, May 2 – Preston North End vs Saints