It seems the Sox want Bregman, but are willing to settle for Arenado if Bregman won't come down from his preferred contract length.

https://www.sportingnews.com/us/mlb/boston-red-sox/news/mlb-insider-says-red-sox-prefer-acquire-six-time-platinum-glove-third-baseman-over-alex-bregman/969adf78578a423470f488d4