There are a lot of ways to build a great bullpen in Major League Baseball. You could slowly develop top pitching prospects and convert them into a flamethrowing relief corps like the 2015 Kansas City Royals did. Or, you could follow the Chicago Cubs' plan of rebuilding the group every year from the free-agent scrap heap. Alternatively, if money is no object, you could just follow the Los Angeles Dodgers' lead and buy all of the best relievers.
Even with all of those proven strategies, leave it to the Boston Red Sox to forge their own path. They've has officially added Ryan Watson to the Opening Day roster, marking the third reliever on the team acquired via the Rule 5 Draft.
Having already had great success with both Garrett Whitlock and Justin Slaten, the Red Sox know how to get the most out of their Rule 5 relievers. Hopefully, that same success can carry forward with Watson in 2026.
Red Sox had fellow Rule 5 picks Garrett Whitlock and Justin Slaten in the room to help inform him. https://t.co/Rx1j9WntqR
— Chris Cotillo (@ChrisCotillo) March 23, 2026
Ryan Watson can continue Justin Slaten, Garrett Whitlock's legacy as Red Sox Rule 5 Draft wins
Watson was definitely a talent-over-results selection back in December, given the 4.26 ERA he recorded in about 50 innings with the San Francisco Giants' Triple-A affiliate in 2025. However, he closed out nine saves and rung up 28.1% of the batters he faced, suggesting there was some untapped potential beneath the surface.
Though he hardly impressed in spring training, the Red Sox remain optimistic about his chances to stick in the majors. He's got two strong secondaries (his slider and curveball both induced whiff rates around 40% last year) and a dependable fastball. Rather than subject him to waivers, the team is betting big on the 28-year-old's stuff to click in Boston.
There's a history of this process working in the form of both Slaten and Whitlock. The former was a 2023 Rule 5 Draft pick from the Texas Rangers, while the latter was stolen from the New York Yankees in 2020. In the years since, both have emerged as dependable bullpen options for Alex Cora.
Whitlock is an especially impressive story who thrived in his full-time conversion to the bullpen last year, emerging as the closer-in-waiting behind Aroldis Chapman. If his World Baseball Classic performance is any indication, he may be even better in 2026.
Slaten is probably the better comparison for Watson as a quality middle reliever, though the Red Sox would take that kind of development from their latest Rule 5 project in a heartbeat. Over the past two seasons, Slaten has covered nearly 90 innings out of the bullpen while logging a 3.43 ERA and 3.02 FIP.
It's hardly traditional, but building a bullpen out of other team's unprotected prospects may soon become a popular model if the Red Sox can go three-for-three with Watson.