in my experience (level 6 with a full academy) as long as you have at least 1 available slot in your squad you will get offered both players and you then have 7 days to decide which one you want to sign.

But I am fairly sure you still get 7 days to make that decision for both new recruits even if you have no available slots... It just means you ether sell a player and then sign the youth academy player or you release the academy players once you have decided not to purchase them.