Uehara, who will wear Josh Beckett’s old No. 19, missed two months with a lat strain for the Texas Rangers in 2012, but he was very effective. In 37 relief appearances Uehara had a career-low 1.75 ERA (7 ER). He had the fourth lowest WHIP in major league history at 0.64.
The downside is that he’s 37, that the Sox probably need to limit his back-to-back appearances, and be careful how often he’s up in the bullpen. He’s definitely a late-inning guy – especially with his $4.25 million salary - who could close some games. Only Dennis Eckersley’s 18.33 strikeouts-to-walk ratio in 1990 was better than Uehara’s 14.33 last season season.
Righties hit only .125 (7 for 56) against him. He spent 10 seasons in Japan, and was signed by the Orioles in 2009 to be a starter. He went to the bullpen in 2010 and since then he’s led the majors with a 10.76 strikeout-to-walk ratio (183 K/17 BB) and has averaged 11.36 strikeouts per nine innings (145.0 IP), the third-highest mark among American Leaguers with at least 125.0 innings over that time.
Over the last three years, he has held righthanders to a .177 batting average (47-for-265), third in the AL during that time (minimum of 200 batters faced). He posted a 0.72 WHIP or lower in consecutive seasons (0.72 in 2011, 0.64 in 2012), becoming just the second big leaguer ever to accomplish the feat along with Eckersley in 1989 and 1990.
In 10 seasons (1999-2008) for the Yomiuri Giants in the Nippon Professional Baseball (NPB) Central League, Uehara was 112-62 with 33 saves, a 3.01 ERA (518 ER/1,549.0 IP) and 1,376 strikeouts. He led the NPB in wins in 1999 and 2002, ERA in 1999 and 2004, and strikeouts in 1999 and 2003.