I'm still getting some pops with Dell'Asta, he's 24 years old and a big man but he's getting his JS popping every 3-4 weeks now which is fine. Still got some life left in him yet. Albeit his potential is Superstar, so that surely helps.
Allstar is good enough to make II worthy guards, but when they cap they will find it hard to compete in ABBL..
Good option is.. (provided you can detach yourself from your favourite players) to sell your completed player, and use the money to buy some half finished trainee, so the performance won't drop too much... but the ceiling will be a lot higher...