​Casey Mize’s first start with the San Diego Padres could not have gone much worse.The former Detroit Tigers right-hander was hammered for eight earned runs on nine hits across just 3⅓ innings, issuing three walks while recording only one strikeout. He also surrendered a home run before being removed.Rough Debut for MizeSan Diego acquired Mize from Detroit shortly before the MLB trade deadline, hoping the former No. 1 overall pick could stabilize its rotation during the playoff push.His Padres debut instead became a short and painful outing.Mize allowed 12 baserunners while recording only 10 outs. The lack of swing-and-miss production was especially concerning, as he finished with one strikeout against three walks.The outing raised his season ERA to 3.40.One Start Does Not Define the TradeMize had not pitched in 11 days before making his San Diego debut after the Tigers scratched him from his final scheduled start as a trade precaution.The extended layoff may have affected his rhythm, but Mize will not use that as an excuse. He now has to regroup quickly for a Padres team that acquired him specifically to pitch meaningful innings down the stretch.Bottom LineCasey Mize’s first start with San Diego was a disaster.He allowed eight runs, nine hits and three walks while lasting only 3⅓ innings. It was hardly the debut the Padres envisioned when they traded for him.Now comes the response.