The Rays have designated reliever Jumbo Diaz for assignment, reports Marc Topkin of the Tampa Bay Times (Twitter links). To take Diaz’s place, they’ve selected the contract of right-hander Andrew Kittredge from Triple-A.

In booting Diaz from their 25- and 40-man rosters, the Rays are moving on from a pitcher they’ve relied on somewhat heavily this year. The same went for Danny Farquhar, whom the Rays designated in late June and outrighted earlier this month after he racked up 35 innings from their bullpen.

Diaz tossed 30 innings before his designation, though he struggled mightily over that span. The 33-year-old flamethrower has registered a bloated ERA (5.70) and a minuscule ground-ball rate (30.7 percent), and his 4.51 FIP isn’t particularly appealing. The righty’s strikeout and walk rates aren’t horrible (8.4 K/9, 4.5 BB/9), though, and he ranks third among relievers in infield fly rate (22.5 percent). Diaz also carries a cheap salary and comes with three years of arbitration eligibility, so he could be a waiver target for another club. That’s how Diaz joined the Rays, who claimed him from Cincinnati back in March.

Regardless of where Diaz goes next, his designation seems to further increase the odds of the Rays acquiring bullpen help before the July 31 non-waiver trade deadline. There have been multiple reports this month connecting the team to relievers, including the Giants’ Hunter Strickland. For now, they’ll turn to the 27-year-old Kittredge, a 45th-round pick of the Mariners in 2008 who hasn’t yet pitched in the majors. The Rays acquired Kittredge from the Mariners over the winter, and he has since posted a 1.90 ERA, 9.35 K/9, 2.08 BB/9 and a 52.2 percent grounder rate through 52 innings and 30 appearances (two starts) with Durham.