Sanchez, 24, returns for his second stint with the Cubs after being optioned to Iowa on Tuesday. He posted no record and a 3.00 ERA (1 ER/3.0 IP) after being selected from Triple-A on July 26. Sanchez has spent part of the last three seasons in the big leagues with the Cardinals (2011-12) and Cubs (2013), combining to go 3-2 with five saves and a 3.38 ERA (18 ER/48.0 IP) in 45 relief appearances. He has struck out 49 batters in 48.0 major league innings while limiting opponents to a .174 batting average against (28-for-161). Sanchez has also limited big league hitters to a .308 on-base percentage and a .273 slugging percentage, a .581 OPS.
The righthander was claimed off waivers from the St. Louis Cardinals on May 21 and has combined to go 1-1 with one save and a 3.71 ERA (14 ER/34.0 IP) in 28 relief appearances between Triple-A Iowa and Triple-A Memphis. Since joining Iowa, Sanchez has limited opponents to a .195 batting average against, including a .152 mark by right-handed hitters, and has not allowed a home run in 24.1 innings.
Sanchez made his major league debut in 2011 and went 3-1 with five saves and a 1.80 ERA (6 ER/30.0 IP) in 26 relief appearances. He split the 2012 season between the majors and minors, going 0-1 with a 6.60 ERA (11 ER/15.0 IP) in 17 outings with St. Louis.
Boscan, 33, returns to the big leagues after spending parts of the last three seasons with the Braves (2010-12), posting a career .263 batting average (5-for-19) in 11 major league contests. The 2013 campaign marks the 17th professional season for the right-handed hitting catcher. He made his big league debut with the Braves on October 1, 2010 after 976 minor league games spanning 14 seasons.
The Venezuelan native is batting .253 (49-for-194) with nine doubles and 18 RBI in 62 games with Iowa this season. He was a non-roster invitee to spring training with the Cubs after signing a minor league deal last November.
Boscan originally signed with the Braves as a non-drafted free agent on July 2, 1996 and has played in the Atlanta (1997-2005, 2008-12), Milwaukee (2006), Cincinnati (2007) and Cubs organizations. He has appeared in 1,169 minor league games, compiling a .224 batting average (840-for-3,753) with 177 doubles, 43 home runs and 397 RBI.
Neal, 25, was claimed off waivers from the Yankees on Monday and added to the active roster on Tuesday. He went hitless in four at-bats with the Cubs.
Guerrier, 35, was acquired from the Los Angeles Dodgers on July 2 and went 2-1 with a 2.13 ERA (3 ER/12.2 IP) in 15 relief appearances with the Cubs.