I think the delay with announcing this fixture will have been to see if the Brighton v Spurs game would go ahead on Friday, 20 April. If it would, we'd have had to play on the Tuesday but with Spurs reaching the FA Cup semi, Brighton can play us on the Wednesday.
I assume that's our preference. Otherwise we'd be playing on Tuesday after the Saturday night game against Spurs, which would be possible but which Pep probably prefers to avoid if we can.