It rained on White Sox rookie Michael Kopech on Wednesday, as it always does when he pitches at home.
The Tigers also poured it on by roughing up the 22-year-old right-hander for four home runs and seven runs in 3 1/3 innings on their way to a 10-2 victory at Guaranteed Rate Field.
The electric stuff that has made Kopech the Sox’ top pitching prospect was absent, and it showed.
‘‘Can’t miss stuff with that kind of velocity,’’ Kopech said. ‘‘And aside from that, the stuff I had wasn’t great, and it got taken advantage of.’’
After a 28-minute delay in the second inning, Kopech — trailing 1-0 on a leadoff homer by Jeimer Candelario in the first — pitched a scoreless third with two strikeouts before being blitzed for six runs and seven hits in the fourth, including homers by Mikie Mahtook, Ronny Rodriguez and JaCoby Jones. The Tigers also had two doubles in the inning.
When he walked off to supportive applause from some encouraging sorts among the paid crowd of 16,036 at Guaranteed Rate Field, Kopech probably took some comfort in knowing he had struck out six batters without his best stuff. But he was probably also wondering what just hit him.
Entering the game, Kopech was 1-0 with a 0.82 ERA in three starts, two of them abbreviated by rain. In a remarkable run of unfortunate timing, this was the third time in as many starts Kopech got wet at home. His big-league debut Aug. 21 against the Twins was limited to two innings, and his second home start Friday against the Red Sox was limited to three.
Kopech’s only dry start came Aug. 26 at Detroit, when he pitched six innings of one-run ball.
Kopech made his mark as the Sox’ top pitching prospect by rising through the minor-league ranks with a four-seam fastball that topped 100 mph at times, but he topped out at 96 mph and worked primarily with a 93 mph heater Wednesday. Three of the four homers he allowed came against his fastball, including a 445-footer by Mahtook and a 433-footer by Candelario, and one came on a hanging slider to Rodriguez.
‘‘I kind of knew going into it not everything was going to be there,’’ Kopech said. ‘‘Early on, I was going to grind through it; that was the plan. But in the fourth inning, I left a lot of pitches up, and I got hit. It’s OK if I’m missing with 96 to 100 [mph]. But with the stuff I had today, I should have been more down in the zone.’’
On the good side, Kopech flashed a good breaking ball at times and induced 11 swinging strikes. He threw 55 of his 82 pitches for strikes, but his fastball command was a problem. With less velocity than usual, it needed to be sharp.
‘‘You’re not going to be sharp every outing, so you just work through it,’’ Sox manager Rick Renteria said. ‘‘Today was one of those days. I told him: ‘Hey, there are a lot of better days for you. I wouldn’t worry about this one.’ ’’
With reliever Dylan Covey pitching for the Sox, a second rain delay of 33 minutes occurred with the Tigers leading 7-0 and two outs in the top of the fifth.
It marked the second consecutive night one of the Sox’ young starters got knocked out early. Right-hander Lucas Giolito, who had a 2.84 ERA in his previous four starts, got only four outs in the Sox’ 8-3 loss Tuesday against the Tigers.
‘‘I just washed it off in the shower,’’ Giolito said. ‘‘Move on to the next one.’’
Kopech will have to do the same. Maybe it won’t rain next time.
‘‘It’s frustrating, but you can’t do anything about Mother Nature,’’ he said. ‘‘I’m eventually going to get a clean one.’’