Mitch Haniger's injury history will continue
Let me start by saying, it pains me to put Mitch on this list. He was the heart and soul of the team for a few years before the team was able to break the playoff drought. You could tell he poured everything he had into this team.
Now, I just don't see a way that Haniger can stay healthy enough to get to the level of production that a lot of people and outlets have him at. For example, Steamer projects he will play in 126 games, and there is just such a small chance that he can stay healthy for that much of it.
I am confident if you guaranteed Haniger played in 120-130 games that he would be a 20+ home run guy and put up a 110 wRC+ doing it. The Mariners should see what Haniger gives them this year as a complete bonus, because if he is healthy for even just 75 games, he will be a very valuable bat (the Mariners should do everything in their power to keep him healthy). Haniger will top last year's games played of 61, but I don't see him getting over 70 games played. Maybe that is enough to be a solid 4th outfielder, but that leaves a lot of at-bats for the taking (Canzone breakout coming).