At the July 31 trade deadline, Cherington added slugger Yoenis Cespedes from the Oakland Athletics and Allen Craig from the Cardinals.
Craig just returned to the Red Sox on Thursday after a stint on the disabled list.
Heading into action on Friday, the Sox ranked last in the American League with 483 runs scored.
Considering the dearth of productive hitters on the free-agent market this winter, Cherington has served the Red Sox well by getting a head start on the '15 roster.
"The players that were made available this trading season or deadline were unique, so we've been able to target those guys, and Ben's assessment of what the free-agent pool is going to look like is going to be pitching-oriented, and so there's a clear-cut plan with the retooling of this roster," said Red Sox manager John Farrell.
Conceivably, Castillo could emerge as the leadoff hitter for a lineup that would also include Dustin Pedroia, David Ortiz, Cespedes, Craig and Mike Napoli.
"Well it's lengthened out and just focusing on the guys that are in uniform today, we've added right-handed power, we've added a couple of middle of the order bats," said Farrell. "We've, I think, discovered a very versatile and valuable guy in Brock Holt. You could say right now we're leaning maybe a little heavy on the right-handed side. Prior to Opening Day next year, there's a lot of time and I know a lot of thought will be put into how we continue to improve this team."
Considering the presence of Cespedes and Craig, Castillo's fit for Boston would seem to be in center field. It remains to be seen what kind of impact the signing will have on young players Jackie Bradley Jr. and Mookie Betts. Bradley was sent down to Triple-A earlier this week after struggling mightily at the plate. Betts has been starting in center for the Red Sox of late, but has the defensive versatility and athleticism to play all over the diamond.
"Those are a lot of things that aren't in place right now, so until we get there, Ben's goal is to build the most talented and deep roster possible, and however that comes about, we'll figure it out as we go," said Farrell.
Ian Browne is a reporter for MLB.com. Read his blog, Brownie Points, and follow him on Twitter @IanMBrowne. This story was not subject to the approval of Major League Baseball or its clubs.