What happened: Boston already exchanged a left-handed pitching prospect for a right-handed infielder. Rule 5-eligible players have typically supplied additional trade capital.

Why it matters: Further buying would require the Boston Red Sox to weigh immediate roster upgrades against years of club control. Those decisions also intersect with offseason 40-man roster protection.

What to watch: Watch whether Boston draws from its remaining pitching depth or preserves the farm system after its first deal.