#6 - Triston Casas - 1B
First base is another one of those positions this year in free agency that isn't very exciting. Rhys Hoskins could be an interesting buy-low candidate coming off an injury and the 40 year old version of Joey Votto is available, but Boston has a really talented young first baseman on their roster in Triston Casas and he deserves a shot to develop even further.
The first couple of months didn't go particularly well. The first month was a disaster and while May was a bit better, he still only had six homers through the season's first two months and there was open speculation that Boston could look to trade him away. However, Casas broke out in the second half with a .317/.417/.617 line with 15 homers.
Unfortunately, Casas' rookie season was cut short due to inflammation in his shoulder. At first look, the injury doesn't appear to be a long-term concern. While Triston's unorthodox preparation and pre-game rituals did rub some folks the wrong way, but he seems to have settled in as Boston's first baseman of the future.
Worst case scenario, Boston has to go with another internal option at first base, but the bet is that he will be just fine and his left-handed bat is a nice fit in the six spot.