It’s already been a tough season for Mariners fans, even for those who are completely on board with the team’s rebuilding project. At 31-46, Seattle sits in last place in the American League West, and with Jerry Dipoto and company unloading anyone who might fetch even a modest return, things likely won’t get any better for a while.



The toughest part about the rebuild is not knowing whether the prospects the club has accumulated since the end of last season will be the ones who lead this franchise out of its doldrums and put an end to the longest current postseason drought in pro sports.



In a best-case scenario, the Mariners’ young building blocks will develop into major-league contributors over the next season and a half and Seattle emerges as at least an interesting team — if not a true contender yet — two years from now. So let’s take a look into our crystal ball to see what the 2021 Mariners might look like.



This...