SEATTLE -- It wasn't the result Nathan Karns was looking for in his Mariners debut, but the 28-year-old right-hander walked away from Saturday's 6-1 loss to the A's believing he just needed to correct one critical mistake that Josh Reddick made him pay for in his five-inning stint at Safeco Field.
"I feel like I didn't pitch bad, I just had bad results at times," Karns said after giving up seven hits and four runs in his first career outing at Safeco. "If I take out that full-count pitch [to Reddick], maybe it's a 2-1 ballgame going into the sixth. That's just the way I look at it, just a couple pitches away from where I want to be."
Karns gave up four singles and a pair of runs in the first -- with two base hits sliding though the left side gap of the infield against defensive shifts -- though he escaped further damage when center fielder Leonys Martin threw catcher Stephen Vogt out at the plate trying to score from first after Martin initially bobbled a base hit by Jed Lowrie.
Karns then settled into a pretty good groove, allowing just a single and walk while striking out four over the next three frames, before Reddick ripped a two-run homer on a 3-2 changeup with two out in the fifth.
"He got through the first, hung in there and got some rhythm going with the curveball and mixing in some off-speed pitches after that," manager Scott Servais said. "Obviously the pitch to Reddick, we'd all like to have back in that situation. But he's got to learn you've got to execute a little better there."
Catcher Chris Iannetta, who accounted for Seattle's lone run with a solo homer in the second, echoed the thought.
"I thought he was one pitch away from having a really good outing," said Iannetta, a 10-year veteran.
Karns, acquired from the Rays in the Logan Morrison-Brad Miller trade in November, beat out James Paxton for the fifth-starter spot in spring. Paxton threw four innings of one-run ball in his Triple-A Tacoma debut on Saturday, allowing just two hits but walking five in a 77-pitch outing.
Karns ran his own pitch count up in a hurry with 35 pitches in the first inning and was replaced after reaching 95 in his five frames.
"They did a great job of battling," Karns said. "At times I was not as crisp as I'd like to start a game, but they definitely worked the counts, fouled off some tough pitches. I think the first out actually came after a couple full-count foul balls and I eventually got him to roll over, but they did a good job not making quick at-bats or letting me work efficiently. They definitely competed."
As for the A's beating the shift a few times, Servais said that won't change what the Mariners are doing. They'll play the percentages and figure to win more than they lose on the defensive positioning. And Karns, whose former Rays team shifted frequently as well, has no issue with that strategy.
"I'm aware that we're going to shift," he said. "We're going to play the numbers. And I'm fine with that. It's tough when it goes against you. And when it works for you, you love it. We anticipated the ball going to that side of the field and it just didn't happen."
Greg Johns is a reporter for MLB.com. Follow him on Twitter @GregJohnsMLB and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.