Good move by Doc. There's no need to play KG in back-to-back games at this point, even if he only plays 15 minutes each game.
In the playoffs, he's going to need off time between each game to let his knee rest and to prevent swelling. Luckily, there's a least a day between every game in the playoffs.
Personally, I think it was a mistake earlier in the season to play KG in a back-to-back situation (at SA, then at Memphis the next night) right when he came back.
Holding KG back until the Wednesday game also gives him a day to recover from his first full practice (which is supposed to happen on Monday) and also gives the fans something to get excited about, since that night will be Fan Appreciation Night. Just a good move, on many different levels, by Doc and the Celtic brain trust.