Harden gave up six earned runs and 11 hits in just four innings in his season debut, a 7-2 loss to the Texas Rangers on Thursday.
“He just made some mistakes with location early in the count,” pitching coach Curt Young said. “It’s definitely going to be a process, and I think he knows that. And I know he’s going to put a lot of work in.
“It just comes down to location, and that’s something he can work on.”
The right-hander had five strikeouts and did not allow a run in his first three innings. However, he allowed two runs in the fourth and four in the fifth.
“He’s around the strike zone, but he left a bunch of breaking balls over the middle of the plate,” Macha said. “And the Rangers are swinging the bats well. The key to his success is the quality of his breaking pitches.
“He’s our fifth starter. He’s our guy, so we’ll go ahead and run him out there. He’s our guy right now.”
Harden, who went 5-4 with a 4.56 ERA in 13 starts last season, started the season in Triple-A Sacramento until the Athletics needed a fifth starter. He allowed three runs and six hits in five innings in his only start for the Rivercats.
“Obviously I’m not happy with the results,” Harden said Thursday. “I felt solid at the start of the game, but I got the ball up over the plate. I need to get that stuff down.”
Oakland left 17 men on base, and the Mariners 16.