It's simple folks.
The Cs have $128,000,000 invested in Gordo. They're not going to jeopardize that for a handful of games, even playoff games. Hayward would have to be 100% healthy and going full bore in practice before the Cs would even think about putting him on the court in a game. It's simply too much risk.
They want to avoid a Grant Hill scenario. Remember that he signed with Orlando (sign & trade) on a 7 year deal and played only 4 games his first year with them due to ankle injuries. He then played 14, 29 and zero games his next 3 years.
We've lost the first year with Hayward - that's a sunk cost - but you don't play around with the nearly $100m left in order to try to get him on the court too soon. You make double and triple sure he's fully healed before you let him sniff the court because a repeat incident blows the entire investment.