PITTSBURGH — The Pittsburgh Pirates head into a crucial series finale and will have Oneil Cruz focus on one specific thing. Cruz starts at designated hitter for the first time in 2026, staying first in the batting order as the Pirates go for the series win over the Arizona Diamondbacks at Chase Field on May 7. He had started his previous 34 games this season in center field, but will instead focus entirely on hitting, taking over from Marcell Ozuna, the usual designated hitter for the Pirates. Jake Mangum will start in center field in place of Cruz, marking just his third start there this season and 17th start of the season in the outfield. Bryan Reynolds remains in left field and Ryan O'Hearn stays in right field to complete the Pirates outfield trio. Why Cruz Might Benefit From Playing DH Cruz has had a solid season so far, slashing .250/.306/.473 for an OPS of .779, with 37 hits, six doubles, nine home runs, 28 RBI and 12 stolen bases on 14 attempts.…