Yes, as long as it is available on catchup.
It does not care whether the live event was before you subscribed or not.
I might be wrong, but NOW on Sports Demand service doesn't cover the full EFL matches on catchup and only offers the "hits" highlights from what i have noticed in the past.
Plus the NOW Sports on Demand such has football takes on average over 24 hours to be added to their service.
I had a quick look at the Sky Sports TV Guide and couldn't see this game on a repeat broadcast (either later today or tomorrow 😠).
And how do I check if its on catch up without subscribing
You don't have to have an active Sports Membership to check out what's currently available on the NOW Sports on Demand service.
There should be a section on the NOW App under Sports on Demand.
Here's a screen shot taken from my Android NOW App off my tablet under the Sports on Demand "Football" section .
You can see from the screen shot that nearly all the EFL matches are hits highlights only and doesn't cover the full replay of the EFL match 😠.
Also don't expect games or sports events to be immediately added to NOW Sports on Demand, where it usually takes more than 24 hours from my experience using their service.