Tulo was declining in his final (half) season in Colorado. i guess there was a chance that it was just an off year and he would bounce back to star levels after that, but he was a league average hitter in 2015, 2016, and well below so far in 2017. This is probably what he's going to be, about ~100 wrc+ in a typical season. If his defence dips on top of that, then it will get ugly.