The Red Sox have made clear throughout the offseason that adding to the club’s starting rotation is their top priority this winter but MassLive’s Chris Cotillo reports that Boston’s pursuit of rotation arms hasn’t stopped them from looking elsewhere, even beyond their reported pursuit of outfielder Teoscar Hernandez. Per Cotillo, the Red Sox also have interest in righty reliever Robert Stephenson and infielder Amed Rosario, though Cotillo goes on to caution that it’s uncertain how strong the club’s interest is in either player.
Rosario, 28, made his big league debut for the Mets in 2017 and was essentially a league average starter at shortstop in Queens and (after being included as part of the return package for Franciscor Lindor) Cleveland from 2019-22 as he slashed .282/.315/.412 while playing defense that fluctuated from above average to well below average on a year-to-year basis. 2023 was something of a down year for Rosario, as he slashed just .265/.306/.369 with brutal defensive numbers in 92 games for the Guardians before being swapped to the Dodgers midseason, with whom he saw significantly reduced laying time. In all, Rosario finished the season with a wRC+ of 88 and just 0.2 fWAR, the worst full season of his career. Rosario clocked in as the 39th free agent on MLBTR’s annual Top 50 MLB free agents list, where we projected him for a two-year, $18MM deal.
Despite Rosario’s many flaws, he’d nonetheless be a sensible addition for a Boston club that got the second-worst production in the majors from the keystone last season. Even Rosario’s .263/.305/.378 slash line from last season would be a significant improvement over the .240/.286/.376 slash line Red Sox second baseman posted in 2023, and Rosario performed solidly on defense at second base in 36 games with the Dodgers at the position last year, his first taste of the role at the big league level. While Rosario may not be the most impactful free agent available on the market, the Red Sox would shore up their depth at a clear position of need by adding him and would do so without blocking the club’s top infield prospects such as Marcelo Mayer and Nick Yorke from playing their way into the big leagues later in the year.
Stephenson, on the other hand, is coming off a much stronger platform season. The 30-year-old right-hander was a first-round pick in the 2011 draft by the Reds and made his big league debut as a starter back in 2016. Stephenson struggled badly in the role for parts of three seasons in the majors before eventually converting to the bullpen full time in 2019, where he found more success. The righty posted a 3.76 ERA (125 ERA+) and a 3.63 FIP in his first season as a full-time reliever, and after being limited to just ten innings of work during the shortened 2020 season was traded to Colorado in exchange for Jeff Hoffman. Stephenson’s first season with the Rockies went exceptionally well, as the righty posted a 3.13 ERA with a 3.63 identical to that of his 2019 campaign.
Stephenson struggled in the 2022 season, which he split between the Rockies and Pirates, and started off 2023 on a rough note by allowing nine runs (eight earned) in just fourteen innings for Pittsburgh. Stephenson’s fortunes quickly turned when the calendar flipped to June and the Pirates shipped him to the Rays, with whom he would have the most dominant stretch of his career. After changing his pitch mix to replace his slider with a cutter as his primary breaking ball, Stephenson struck out an incredible 42.9% of batters faced during his time with the Rays while walking just 5.7%. The top-level run prevention numbers are just as impressive, as the righty posted a 2.35 ERA and 2.45 FIP across 38 1/3 innings of work with the Rays this year. That strong production led MLBTR to rank Stephenson as the offseason’s 27th-best free agent, with a prediction of a four-year, $36MM deal.
That being said, the fit between Stephenson and Boston isn’t quite as clean as it is with Rosario. The Red Sox boasted a strong bullpen in 2023 anchored by veteran right-handers Kenley Jansen and Chris Martin, to say nothing of solid campaigns from the likes of Josh Winckowski and John Schreiber. Such a solid mix of righties in the club’s bullpen leaves the Red Sox seemingly unlikely to outbid bullpen-needy teams such as the Rangers, Astros, Cardinals and Cubs for Stephenson’s services. That being said, Cotillo suggests that the Red Sox may see a Stephenson signing as a method to leverage that bullpen depth and work out a trade of Jansen, Martin, or Schreiber. Speculatively speaking, a deal packaging a top relief arm like Jansen or Martin with a young outfielder like Wilyer Abreu or Jarren Duran could be enticing for a club with starting pitching depth available such as the Astros or Marlins that likely needs to improve other areas of the roster.
