The signing deadline for this year's drafted players has passed, with few surprises -- every true first-rounder signed for the first time since 2007 -- and I've already reordered the top 50 prospects in the minors (although that ranking already has come to dust courtesy of a few key promotions). Here now is a very temporary ranking of the five strongest farm systems in baseball.

Two teams not on this list who at least have a chance to make a big leap between now and August 1 are the Philadelphia Phillies and Cincinnati Reds, two teams that need to sell without remorse or compunction at this year's trade deadline.

Plenty has changed since I last ranked the farm systems (back in January), so without further ado, here are the current top five major league farm systems:

1. Boston Red Sox

January rank: 5

Number of top-50 prospects: 5

Top prospects: Rafael Devers, 3B (ranked 8th in top 50); Yoan Moncada, 2B (11); Manuel Margot, CF (14); Henry Owens, LHP (37); Javier Guerra, SS (48)

The Red Sox have as much potential ceiling -- in terms of players who have at least a fighting chance to become well-above-average regulars or more -- as any organization in baseball, as well as tremendous depth in both position players and pitchers. This sets them up well to make a trade for some major league impact now or this winter.

The top three players in their system are all international signings who have shown huge early promise, as has Guerra and their main signing from July 2, 2014, right-hander Anderson Espinoza, who is already throwing well at age 17 in the Gulf Coast League. They also added, via this year's draft, Golden Spikes Award winner Andrew Benintendi, a power-hitting center fielder with above-average speed who's off to a great start in short-season ball, while fast-rising first baseman Sam Travis (former teammate of Cubs rookie Kyle Schwarber at Indiana) already has hit his way to Double-A. And they still have players like third baseman Garin Cecchini, shortstop Deven Marrero and center fielder Jackie Bradley Jr., who would be on the major league rosters of many other MLB teams but are completely blocked in Boston.