You will likely regret not pulling the exhaust manifold and just replacing that one duff injector.
That would likely be my first guess, but I would also be looking at the valve gear for that cylinder if my pop tester showed the injector as good - well not stuck open or just jetting.
It could be a non-opening inlet valve. Compression can be roughly checked by turning the engine slowly - a dead pot would be easy to spot, particularly knowing when to expect it.
Another non-invasive test would be a compression check on that cylinder.
All better alternatives to pulling it to pieces to find the fault.
Anyhow the deed is done. If the injectors prove OK, the first place I would be checking is the inlet tappet on that cylinder.