According to Baseball America, the Boston Red Sox currently have the fourth-best farm system in all of baseball. In the past year or two, the Red Sox have promoted Xander Bogaerts, Mookie Betts, Eduardo Rodriguez, and Blake Swihart from Triple-A Pawtucket, which has hurt the ranking of Boston's farm system. Additionally, Henry Owens lost his prospect status after starting 11 games in 2015 for the big league team.
Furthermore, in November of 2015, the Padres and Red Sox completed a trade that sent four-time all star closer Craig Kimbrel to the Boston Red Sox for highly ranked prospects Manuel Margot and Javier Guerra, as well as Carlos Asuaje and Logan Allen. While this move certainly hurt Boston's farm system depth, they picked up one of, if not the, best closer(s) in all of baseball and still feature one of the best farm systems in baseball.
Everybody knows about the top prospects in the Red Sox farm system. Yoan Moncada, Anderson Espinoza and Andrew Benintendi seem destined for greatness, as they tear up the minor leagues. Moving forward, I would be extremely surprised if Boston dealt any of those players.
However, the Red Sox have a ton of depth around the infield in both the minors and major leagues. Specifically, up the middle (SS,2B) may be the deepest position(s) for the Red Sox. Dustin Pedroia appears healthy, albeit only a couple games into the 2016 season. Super utility man, and current left fielder, Brock Holt, started his career at second base, as well. Xander Bogaerts is one of the best up and coming players in the league, and has rightened the ship defensively after a shaky 2014 campaign.
Second baseman Yoan Moncada is currently the top prospect in the Red Sox farm system, but appears to be destined to switch over to third base because of his large frame. Aside from Moncada, Deven Merrero, Mauricio Dubon, Marco Hernandez, and Wendell Rijo round out the top 30 prospects at the position(s).
The Red Sox also feature a plethora of pitching in their top prospect pool, but aside from the aforementioned Anderson Espinoza, none appear to be ready to blossom into top-end of the rotation talent in the immediate future.
With so much depth around the infield, and an apparent log jam as most of them will never suit up for the Red Sox, do not be surprised if Dave Dombrowski looks to add elite pitching at the Trade Deadline with the prospects mentioned above.