"It's definitely good to get the timing going and get synced up right," said Haniger, who is expected to start in right field this season after being acquired from the D-backs. "I was just trying to hit the ball hard. Today felt a lot better. I'm making progress."
Kopech, a 20-year-old acquired from the Red Sox in the Chris Sale trade, was touching 100 mph on scout's radar guns but surrendered four runs on three hits and a walk in his one-inning debut. He left a slider up to Haniger on the home run and also gave up an RBI double to Nelson Cruz.
Hernandez, gearing up for his 13th season with the Mariners, tossed two innings of one-run ball, allowing three hits in a 33-pitch outing. Rookie Andrew Moore followed with a pair of scoreless frames, allowing one hit.
Mariners shortstop Jean Segura and left fielder Guillermo Heredia continued their hot starts. Segura went 2-for-3 with two runs and is 6-for-8 with a homer and two doubles on the spring. Heredia went 2-for-3 with a triple and two runs to put him at 5-for-9 in three games.
Shortstop Tim Anderson had a pair of hits for the White Sox split-squad team.
Mariners Up Next: Drew Smyly, acquired in a trade with the Rays, makes his first start in Wednesday's 12:05 p.m. PT game against the Indians in Goodyear. Closer Edwin Diaz will make his first Cactus League appearance, while hard-throwing prospect Thyago Vieira is also among the relievers slated to throw. The game will be available on Gameday Audio.
White Sox Up Next: James Shields makes his first start of the spring as the White Sox play host to the D-backs with a 1:05 p.m MST first pitch at Camelback Ranch. Jake Petricka also will be making his Cactus League debut, with David Robertson, Nate Jones and Zack Burdi scheduled to take the mound.
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Greg Johns is a reporter for MLB.com. Follow him on Twitter @GregJohnsMLB, read his Mariners Musings blog, and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.