The Arizona Diamondbacks are designating veteran right-handed reliever Paul Sewald for assignment after his recent funk, multiple outlets reported Monday afternoon. Sewald has 24 saves but was recently demoted from the closer’s role after failing to convert an opportunity against the Pittsburgh Pirates on July 28. Moving Sewald opens a roster spot for right-hander Zack Littell, whom the Diamondbacks reportedly agreed to terms with on Sunday. Littell, 30, was 7-8 with a 4.97 ERA in 23 appearances (14 starts) for the Nationals. Over nine seasons, Littell is 41-37 with three saves and a 4.05 ERA in 257 appearances (93 starts) with six teams.