3 free agents the Pirates should pursue to bridge the gap to Konnor Griffin

The Pittsburgh Pirates have the consensus number one prospect in all of baseball: Konnor Griffin. Griffin was their first-round pick in 2024 and has quickly risen to prospect stardom. He flew through the minor leagues in 2025, starting the year at A-Ball Bradenton and ending the season at Double-A Altoona. While it's very likely Griffin will be the Pirates' shortstop by the end of 2026, and could very well be in contention for National League Rookie of the Year, fans shouldn't hold their breath on him starting the year in MLB. While the Pirates have depth at shortstop, they could add more this offseason with one of these free agents to help bridge the gap until Griffin is in the bigs.

Extra depth at shortstop until Konnor Griffin is ready could greatly help the Pirates out in 2026.

Willi Castro

Willi Castro established himself as a quality super utility man with the Minnesota Twins. From 2023 through 2025, Castro batted .250/.335/.398 with a .322 wOBA and 107 wRC+ while with the Twins. The switch-hitter had a respectable 8.4% walk rate while striking out 24% of the time. He was never a big home run hitter, but his .149 isolated slugging percentage wasn't that much worse than the average batter. Plus, he's now gone back-to-back seasons with double-digit home runs.

2025 was one of Castro's worst seasons yet, but that was mainly because of his struggles after getting traded to the Chicago Cubs at the trade deadline. He was putting up a .245/.334/.407 line with a 109 wRC+ with the Twins prior to the trade. However, he slashed just .170/.245/.240 with a 40 wRC+ in the final 110 plate appearances of his season while suiting up for the Cubs.

Since 2023, Castro has played all three outfield positions and all but one infield position, that being first base (excluding catcher). Castro's last three seasons at shortstop have been a mixed bag. In 517 innings, he has -9 defensive runs saved, but +3 outs above average. Castro isn't a Gold Glove-caliber defender at any position, and grades out better in OAA than DRS at most positions on the diamond. 

Castro is the best short-term answer at shortstop for the Pirates, given that he would still be valuable to the Bucs, even after Griffin's promotion to the major leagues. He has been a solid hitter for parts of three seasons now. He can give the Pirates some help on offense (which,as we all know, they desperately need) and versatility. Not many utility players can provide both defense and offense like Castro can.

Amed Rosario

Amed Rosario may have only appeared in 64 contests with the Washington Nationals and New York Yankees last season, posting 191 plate appearances, but it was one of the utility man's best showings at the dish. He slashed .276/.309/.436 with a .321 wOBA and 106 wRC+. Rosario hit six home runs while posting an ISO of .160, which is a single-season career-best for him. He also set career-bests with a 16.2% strikeout rate, a 91.2 MPH exit velocity, and 6% barrel rate. Rosario typically has a low walk rate, as he only drew a free pass 3.7% of the time.

There were some solid numbers under the hood as well. He had a .341 xwOBA and .458 xSLG%. His xBA approached .300, coming in at .298. It was a small sample size, but he wasn't horrible for a utility man in 2024 either, with a .280/.306/.380 line and 96 wRC+ over 346 plate appearances. Between his last two years, he has produced roughly league-average numbers with the bat.

Rosario has seen more time at other positions in recent seasons. Most of his time in the field over the last two seasons has been at second and third base, with some innings in right field mixed in. He only logged a pair of frames at short this year, and it's for a good reason. He has -41 DRS and -61 OAA at shortstop for his career. Since making his debut back in 2017, he has the second-fewest DRS and OAA among all shortstops.

But if the Pirates are that worried about Rosario's defense at shortstop, he doesn't have to be their bridge at that position specifically. He could push Nick Gonzales to shortstop, with Rosario and Jared Triolo on hand for second base/utility. Even though his defense is lackluster, he could give the Pirates decent hitting, a glove they can put wherever they need, and some middle infield depth until Griffin is promoted.

Jorge Mateo

Castro and Rosario are options who bring upside with the bat, but not very much in terms of defense at shortstop. Jorge Mateo is the complete opposite. Mateo has been an above-average defensive shortstop for his career, with +13 DRS and +6 OAA at the middle infield position. He also grades out as an average defender at second base and center field. However, his bat has been lackluster, and that's putting it mildly.

Mateo only stepped to the plate 83 times this season and struggled in the microscopic sample size, but his previous time with the Baltimore Orioles never saw the speedy utility man produce much with the stick, either. Since 2022, Mateo has a .218/.264/.363 triple-slash, a .272 wOBA, and a 75 wRC+ over 1,174 plate appearances. Mateo does not walk frequently (5.4% BB%) and has a subpar strikeout rate of 26.1%. He also only posted an 86.4 MPH exit velocity and a 5.3% barrel rate.

There are a few positives of note, though. Mateo's .145 isolated slugging percentage indicates he can occasionally run into one. In 2022, when he was the O's primary shortstop, he went yard 13 times in 150 games. He is also one of baseball's best baserunners. Since 2022, he has 95 stolen bases in 113 attempts and consistently ranks among the fastest runners in the sport. He sports a remarkable +17.4 base running runs above average, which is the 11th most in the league, despite not having played more than 100 games in a season since 2023.

The Pirates struggled with hitting last year, so someone with a wRC+ under 80 over the previous four seasons isn't the most ideal addition. However, Pirates shortstops were only about average defensively this season, with 0 DRS and -1 OAA, and the Bucs as a whole were the fifth-worst team in terms of base running runs above average at -5.7. Mateo could help the Pirates at shortstop alongside Triolo, forming a strong defensive duo with serious speed.