Don't trade Danny if his knee looks rehabilitated. The reason why is simple, If he makes our team better we can topple the heat and win a chance to face the Western Conference Champion next summer. The heat have few options to improve as they have 85 million already tied up contracts. This means not much wiggle room to sign up to 2 people given their current roster.
Danny's current value doesn't mean much without factoring in Lance and Paul. The value of rookie contracts to a championship caliber team can't be overstated. Remember when OKC had Harden, Durant, and Westbrook? me too. What broke that up? needing to pay them. We have a window where for one year we have Lance and Paul at an extreme discount. Their production is that of 2 well payed players. If It works with Danny or Lance coming off the bench and it we're rolling headed towards the trade deadline we shouldn't trade Danny.
Losing Danny for nothing next summer might be worse long term if we don't win this year but we have to remember our core, Paul and Roy are pieces that you can build around. If it doesn't work our decks will be clear in the summer of 2016 of everyone except PG, GH, and possibly Lance. We're in a good position not to panic and move Danny now unless the package we get back is worth losing a lot of flexibility.
A good season is just a good season without a Championship. I think holding Danny represents our best chance in a while to win now. If he can play and is playing well we should not trade him.