Teague went down hill last year before ever coming to Boston. He is actually shooting significantly better from 3, it is his near the rim stuff that has been awful and that just seems flukey to me.
Dominique took a pretty big fall when he came to Boston. Now I get he was old so it wasn't exactly unexpected, but he was no where near the the 26 ppg scorer he was the prior year in Boston. Didn't get to the line as much, shooting percentage down, rebounds down, etc. Again he was old so it is hard to say it wasn't expected, but he was quite simply no where near the player he was.