If the Red Sox wish to spend, and this will certainly be spending, then take a run at 34-year-old right-hander David Robertson, who has been Mr. Consistency throughout his 11-year MLB career. Robertson has already mentioned leveraging the Red Sox against the Yankees as part of his negotiations regarding a new contract.
The 2018 season saw a shift by Robertson in his mound approach with the greater use of a recently (2017) introduced slider tossing it at a 14.4% rate while decreasing his use of a fastball to a career-low 42.5% rate. Robertson also maintained his fastball velocity (92.3) and also tossed a greater number of curves (42.9%) than his career average (29.3%).
Robertson is generally considered a set-up for the closer but does have a history of closing with 137 career saves and a 79.7% save percentage. Robertson is prone to walks with a 3.6 BB/9 for his career, but that is offset by a 12.0 K/9 and 6.7 H/9 for his career. Robertson is simply an élite out of the bullpen who is quite durable pitching 60+ games for the last eight seasons. A sure thing for late innings.
Making a run at Robertson and signing him would weaken a formidable Yankee bullpen and represent a coup for Boston and most certainly add one of the top relief arms in the game, but oh that money! Robertson earned $13 MM from New York in 2018 and is set to match and improve upon that.
VERDICT: Make an offer