At this point, I think based on FIGC definitions for home grown and U-21 players (Pjaca included as under 21 as he was under 21 at the start of the calendar year), we have the right number of squad players. So, if Zaza leaves, we should expect a new arrival in midfield. Allegri kind of made it clear we are not after another forward.
So my guess is, we get 1 mid if Zaza leaves. We get 2 mids if Pereyra / Hernanes leaves.
However, the press links to any new mids is relatively WEAK. The strongest links are that of a Zaza exit to Wolfsburg and Pereyra to Watford. Links to players like Eriksen, Isco, Fabregas, and even Matuidi is weak. Brozovic is the strongest link so far.
I have a sneaking suspicion that whoever comes could be out of left field. Either that, or we end up with a panic buy.
I just hope that we sort out the new arrivals before we deal on the sales.