The 52-32 Red Sox lineup has consistently featured and carried some marginal performers like Chavis, Dalbec, Gonzales and Santana, while the bullpen backend of Andriesse and Rios are seat holders out there.
Dropping Santana in favor of almost any LH hitting 1Bman would be one step towards strengthening. Chavis, IMO, has already missed the bus to his MLB future with Boston. Dalbec has maybe 1-2 years to catch that bus, but is clearly not yet primetime. Marwin is a Cora favorite and will be a part of the mix for 2021 to the end.
Sale and Brasier represent some hope for improvement , and Valdez could be back when they DFA Andriesse. Arroyo's return from IL may be considered an upgrade. Duran's arrival in the midst of a pennant race will be interesting to see. So, Chaim may need only one move LH 1Bman, some returns from IL and no further big injuries to roll on to take the AL East.