Since returning from the disabled list about three weeks ago, he's been slow to regain his timing, going just 10-for-45 (.222 average) with no home runs and two RBIs in the month of July.
"My timing's getting there. I'm trying not to get as frustrated. Every time I square some up it's usually at somebody, but it's coming," Hart said. "I'm trying to stay focused on the fact that it is coming and not try to do too much."
With the acquisition of Kendrys Morales, Mariners manager Lloyd McClendon said his plan is to platoon Hart and left-handed hitting Logan Morrison at first base. Hart's only appearance at first base this season came April 18, when the Mariners faced Miami in Interleague Play.
"I knew with [Justin Smoak] going down and Willie [Bloomquist] kind of tweaking his leg yesterday, I thought there was a chance," Hart said of the position switch. "I wasn't really shocked with being in there."
Hart missed the entire 2013 season when he had microfracture surgery on both knees, but McClendon insisted the 32-year-old Kentucky native is ready to play in the field after DHing for most of the season.
"He doesn't have any restrictions at first base. I was asked the other day about Corey playing the outfield. He doesn't have any restrictions there, either," McClendon said. "I just don't know when I can get him out there."
Hart hopes the new role will help him improve at the plate.
"Lloyd's staying with me and he believes in me," he said. "So I'll just keep working, and hopefully actually playing in the field might get me going even more."
Adam Lewis is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.