As the team's pitching staff struggles, the Red Sox are making changes to its coaching staff and bullpen.

The team is firing pitching coach Juan Nieves, as the Sox have the second worst ERA in the majors. Nieves joined the Sox before the team's 2013 World Series run.

According to several reports, the Sox are also designating right-hander Edward Mujica for assignment. That means the team has ten days to release, trade, or grant waivers to the reliever, who has a 4.61 ERA this season.

The 31-year-old came to Boston before 2014, after posting an All-Star season with St. Louis in 2013.