What would Red do in this situation?
Guess is Ainge will do it to...
In the world of "bigs" Red (like any other evaluator) wanted a couple things.
Defense--Not over the top, but a healthy defensive attitude from the player. Focus on his man. Good motor. Willingness and timing to leave his feet. A player who will commit to defense. Not that common if you study the league now, lot of bigs "look" like they are trying. Accurately reacts to the loose ball/rebound as body control is efficient.
Offense--Can hit a shot from the outside. Has efficient natural shooting form. Can rise in close and make the j. Doesn't freeze up at the FT line. Has the footwork and acceleration to help his team up the court on the break. Natural body control has him ready to plant, receive and shoot in minimum amount of time.
"Willingness"
There is a lot to be said of this trait in a big man. It is hard to haul around a giant body.
Red had Russell, Cowens and Parish. Ainge had Garnett. Each of them, in their own way, were "willing" to commit on defense and had offensive skills in balance.
If Ainge sees any of this potential in Isaac? He will take him.
My view isn't worth much, but, Isaac hustles. He moves quickly and efficiently for a big, but still, it his desire that shows through. Thomas, Bradley and Smart "try" their butts off. It's what makes them good.
Whether he's another big that doesn't translate to the NBA or a top player can only be discovered when he is up against top competition and that level isn't found at the college level.