He’s not on the market anymore.
The second year of the deal is not guaranteed.
This is another of the smart gamble moves by the Nets, taking a chance on a player who didn’t fit elsewhere but has some potential (like D'Angelo Russell). Zeller is fairly athletic and moves well for a big man, but he is not efficient on offense and struggles to defend in space. He has a midrange game, but if he could get some easy buckets at the rim he’d be much more efficient.
He will get his chance with the Nets to prove he still has a role in the NBA.