PHOENIX — Edwin Diaz had a rare night of struggles, facing runners on the corners with no outs in a one-run game. A rundown and two fly outs later, the Seattle closer reached a rare milestone. Now it’s time for Diaz’s manager to get a haircut. Diaz worked out of a jam in the 10th inning to become the 17th player in big league history with 50 saves in a season and Denard Span hit a solo home run in the top half to lift the Mariners a 4-3 win over the Arizona Diamondbacks on Saturday night. Diaz made a bet with Scott Servais in April that he’d hit 50 saves this season and now the Mariners manager has to pay up by getting a haircut like his closer’s — possibly as early as Sunday. “They said they had a barber here, so he might get it tomorrow,” Diaz said.