One of the appealing aspects of signing Mahrez and Jorginho is that neither of them will be at the World Cup and will be able to have a full pre-season.
1) this will allow them to get maximum exposure to Pep's methods from Day 1
2) they will be fully match fit ready for the season starting, whereas there will be players who, dependent on how far they advance in the tournament, will be coming back after a break in a deconditioned state in late July, early August.
A combination of 1 and 2 should hopefully lead to both of them allowing us to still have a strong start to the season while other players get back to full match fitness.
Fingers crossed both players will be signed prior to the start of pre-season.