Machi, 33, was designated for assignment on July 20. In 33 outings for the Giants this season, all in relief, he went 1-0 with a 5.14 ERA (20 ER/35.0 IP) and 22 strikeouts, making 23 scoreless appearances. Since returning from a stint on the 15-day disabled list with a left groin strain on June 23, he has given up four runs in 8.2 innings (4.15 ERA). This season, he has held left-handed batters to a .120 batting average (6-for-50) and just one extra-base hit.
In his big league career, all since 2012 with the Giants, Machi has gone 11-2 with two saves and a 3.24 ERA (58 ER/161.0 IP) and 128 strikeouts. In 122 appearances between 2013 and 2014, the first two full seasons of his major league career, the native of Venezuela ranked 10th among National League relievers (min. 100.0 IP) with a combined 2.49 ERA (33 ER/119.1 IP). He was a member of last year's World Series Champion Giants team, making seven appearances with no record while allowing five runs in 5.2 postseason innings.
Buchholz, 30, was placed on the 15-day disabled list on July 11 with a right elbow strain. In 18 starts this season, he is 7-7 with a 3.26 ERA (41 ER/113.1 IP) and 107 strikeouts. A two-time All-Star selection (2010, 2013), Buchholz has gone 73-51 with a 3.85 ERA (440 ER/1028.1 IP) and 806 strikeouts in 168 career major league games (166 starts).