The announcements were made by Executive Vice President/General Manager Ben Cherington.
Crawford, 31, is scheduled to undergo ulnar collateral ligament reconstruction (Tommy John surgery) on his left elbow on Thursday, performed by Dr. James Andrews. He has hit .282 (33-for-117) with 10 doubles, two triples, three home runs, 19 RBI, 23 runs and five stolen bases in 31 games for the Red Sox this year after coming off the disabled list on July 16, including a .306 clip (22-for-72) in August with a Major League best 10 doubles in the month. Crawford began the 2012 season on the 15-day disabled list while recovering from left wrist surgery and was transferred to the 60-day DL on May 3. A four-time American League All-Star who was signed by the Red Sox as a free agent in December of 2010, Crawford is a career .292 hitter (1,642-for-5,615) with 254 doubles, 114 triples, 118 homers, 667 RBI, 853 runs scored and 432 stolen bases in 1,396 Major League games with Tampa Bay (2002-10) and Boston (2011-12).
The 27-year-old Valencia has played in four games for Boston this year after an August 11 recall, appearing at third base in all four contests while going 1-for-8 (.125) with an RBI at the plate. Acquired by the Red Sox from the Twins on August 5, he also played in two contests for Triple-A Pawtucket August 9-10, going 3-for-7 (.429) with two doubles, two RBI, two walks and a run. Prior to joining the Red Sox organization he split time in 2012 between Minnesota (34 games) and the Twins Triple-A Rochester affiliate (69 games). Originally selected by the Twins in the 19th round of the 2006 First-Year Player Draft, the right-handed hitter owns a .259 average (258-for-997) with 52 doubles, four triples, 24 home runs, 130 RBI, 106 runs and 63 walks in 277 career Major League games with the Twins (2010-12) and Red Sox (2012).
Nava, 29, had been on the disabled list since August 1 (retroactive to July 29) with a left wrist sprain. In two rehab games with Triple-A Pawtucket over the last two days, he went 1-for-4 with a home run and two walks. The switch-hitter has appeared in 65 games for the Red Sox this season, batting .251 (50-for-199) with 17 doubles, four home runs, 27 RBI, 32 runs and 32 walks. He was selected to the active Major League roster on May 10 after beginning the season with 27 games for Triple-A Pawtucket, and his .373 on-base percentage ranks fourth among American League outfielders with at least 225 plate appearances this season. Signed by the Red Sox as a minor league free agent in January of 2008, Nava has appeared in 125 career Major League games over the 2010 and 2012 seasons, and tallied a .247 average (89-for-360) with 31 doubles, a triple, five home runs, 53 RBI, 55 runs, 51 walks and four stolen bases.
Padilla was placed on the disabled list on August 8 (retroactive to August 6) with right arm tightness. The 34-year-old right-hander is 4-1 with one save, a 4.62 ERA (20 ER/39.0 IP) and 43 strikeouts compared to 11 walks over 41 relief appearances for Boston this season, including a 3.38 ERA (11 ER/29.1 IP) in his last 32 games since May 6. He leads the team with 20 holds, sixth most in the American League, and four wins out of the bullpen, tied for ninth most in the circuit, and has stranded 88.5 percent of inherited runners (23 of 26) for the second-best rate among AL qualifiers. In 371 career Major League outings (237 starts) with the Diamondbacks (1999-2000), Phillies (2000-05), Rangers (2006-09), Dodgers (2009-11) and Red Sox (2012), he owns a 108-91 record with six saves, a 4.32 ERA (749 ER/1,560.1 IP) and 1,113 strikeouts.