In the past few weeks, the Houston Astros have made a couple moves to attempt to bolster their bullpen, but they may not be done.

Fox Sports' Ken Rosenthal reports that the Astros are still looking to add a left-handed reliever, even after the additions of Francisco Liriano and Tyler Clippard to the team's struggling bullpen.

Liriano came to Houston before the trade deadline and was immediately moved to the bullpen, as the team sought to improve its left-handed options. However, after struggling with a 5.88 ERA as a starter for the Toronto Blue Jays, Liriano has not improved much in four appearances with the Astros, allowing four hits, three walks and two runs in 2 2/3 innings of relief.

The Astros acquired Clippard, a righty, from the Chicago White Sox on Sunday, marking the pitcher's third team this season after starting off as a member of the New York Yankees. He was one of the top relievers in baseball through May, but the wheels came off starting in June when he put up an 11.17 ERA for the month. Clippard rebounded with a 1.80 ERA across 11 appearances with the White Sox.

Houston's bullpen ranks 19th in the majors with a 4.26 ERA this season. After Liriano, left-handed relievers Tony Sipp (now on the DL) and Reymin Guduan have struggled to post 6.47 and 5.54 ERAs, respectively.

--Sam Henken