I wonder what the average age is of each team's playoff rotation (only the ones receiving meaningful minutes).
The below numbers are from basketball-reference and some of their age listings may be off a bit, so these may skew a little low by a year.
Here's a look at the Warriors:
Klay (28) - 38 mpg
Dray (28) - 38 mpg
Durant (29) - 37 mpg
Curry (30) - 31 mpg
Iggy (34) - 28 mpg
Looney (21) - 21 mpg
Livingston (32) - 18 mpg
Cook (24) - 16 mpg
McGee (30) - 13 mpg
West (37) - 12 mpg
The average age of the top five guys is just shy of 30. The bench is a mix of younger and older.
Rockets:
Harden (28) - 35 mpg
Paul (32) - 33 mpg
Ariza (32) - 32 mpg
Capela (23) - 32 mpg
Gordon (29) - 31 mpg
Tucker (32) - 30 mpg
LMAM (31) - 19 mpg
Green (32) - 15 mpg
Ryno (29) - 11 mpg
Nene (35) - 10 mpg
The average age of their top 6 guys (all playing 30+ mpg) is about 29.
The bench trends a bit older.
Cavaliers:
LeBron (33) - 41 mpg
Love (29) - 33 mpg
J.R. (32) - 32 mpg
Hill (31) - 26 mpg
Korver (36) - 26 mpg
Green (31) - 22 mpg
Hood (25) - 17 mpg
Clarkson (25) - 17 mpg
Nance (25) - 16 mpg
TT (26) - 16 mpg
Calderon (36) - 14 mpg
Average age of the Cavs top 5 is 32 years old. If you weighted the minutes it'd be closer to 33 years old since LeBron is playing so many minutes.
Definitely an OLD team, but they have several 25/26 year olds on the bench thanks to their mid-season dealing.
Now the Celts:
Rozier (24) - 37 mpg
Horford (31) - 36 mpg
Tatum (20) - 35 mpg
Brown (21) - 32 mpg
Smart (24) - 31 mpg
Morris (28) - 29 mpg
Baynes (31) - 20 mpg
Semi (23) - 15 mpg
Larkin (25) - 14 mpg
Monroe (27) - 10 mpg
Average age of the top 6 is about 25 years old. The bench is about the same. The Celts are MUCH younger than any of the other conference finalists. They'd still be significantly younger if their 26 year old star PG and their 28 year old star wing were not hurt.