The game at Hogan Park had previously been reported as a 7pm kick-off, but the Iron have confirmed that's not the case.
Brian Laws' side also face Cobh Ramblers at St Colman's Park two days later, kicking off at 7.30pm.
Meanwhile tickets for United's pre-season home clashes with Northampton Town and Cambridge United are £10 for adults and £6 concessions.
Juniors only have to pay £1, supporters can pay at the turnstile.
The Iron's finalised pre-Season schedule:
14-07-05 - Grimsby Town (Lincs Cup) A - 7.30pm
16-07-05 - Brigg Town A - 3pm
18-07-05 - Limerick A - 7.45pm
20-07-05 - Cobh Ramblers A - 7.30pm
25-07-05 - Northampton Town H - 7pm
26-07-05 - Winterton Town A - 7pm
27-07-05 - Cambridge United H - 7pm
28-07-05 - Goole Town A - 7pm
30-07-05 - Scarborough A - 3pm