Google has been slow but surely releasing all the Source codes and also factory images for the their Nexus devices . But earlier today they published the Nexus 9 factory image over at Google Developer and just now the have published the Nexus Player “fugu” factory image 5.0 (LRX21M)
Nexus Player & Nexus 9 Factory Image
For more information on all the Nexus device Factory images visit Google Developers Nexus
if you want to directly download the Factory image here is the link
Source: Google Developers