Marmol, 30, has pitched to a 5.86 ERA and 1.70 WHIP in 27 2/3 innings this year while saving two games in five chances. Since saving 38 games with a 2.55 ERA during his breakout 2010 campaign, he has posted a 4.13 ERA and 1.49 WHIP.
During that 2010 season, Marmol set a new MLB season record by striking out 15.99 batters per nine innings. He smashed the previous record (14.98 K/9), which was set by Eric Gagne in 2003. For his career, Marmol has struck out 11.7 batters for every nine innings thrown. Of course, he has also walked 6.1 batters for every nine innings, which was a major problem.
Marmol ranks second on the franchise's all-time games pitched list (483) and third on its all-time saves list (117). The Cubs owe him $9.8 million this year, the final season of his three-year, $20 million contract. Marmol will undoubtedly clear waivers at that salary, but another team will be able to sign him for the prorated portion of the league minimum if he is released.
In other roster news, the Cubs have released third baseman Ian Stewart according to CBSSports.com's Jon Heyman. Stewart recently criticized the organization on Twitter for not calling him up from Triple-A Iowa, then was suspended for his comments.
Outfielder Brian Bogusevic was recalled to take Marmol's roster spot. The 29-year-old was hitting .319/.418/.512 with 10 home runs and 16 stolen bases at Iowa.