I think Manninger will probably be leaving. A 'keeper of his calibre won't stick around to be third choice.
Why would Kirev (or Pinsoglio) stay at Juve as third choice and play maybe one match a season, probably zero?
They're not like Chimenti, at the end of their careers. They'll either be loaned out or sold.
Maybe it is unfair for promising young players like Kirev or Pinsoglio to stay on the bench the entire season without any single match,but it is also very risky if one of these young GKs is a Gigi's backup,especially when u knw that Gigi these years spends many monthes of the seasons recovering from injuries.
But if u think a bit u will find that even Storari is old and any of those GKs can be 2nd GK after just couple of yrs and can also get the chance to be 1st GK after not more than 5 yrs as Gigi himself would retire.
If i were Kirev or Pinsoglio i would sit in the bench even for 5 yrs as long as the result of that will make me Juve's 1st GK.
Remember Manninger 9 yrs back,he made that mistake,as he moved away from Arsenal cause of lack of play,but just 2 yrs after his departure,Seaman got very old and Arsenal released him and started searching for a new GK,but Alex wasted that chance and at the time he was playin in France or some where lesser than EPL.
Tacchinardi(our legend

),came to juve in 94 and was always used as a backup for Deschamps(another legend

)till DD departure in 99,and from that moment he started his legendary story with Juve.