"That was a tough one," said a relieved Ackley, who had only one other routine catch the rest of the night in Seattle's 5-4 win in 10 innings. "I don't think I'd even got a ball like that when I was down in Triple-A, and right out of the gate, you get the tough ball, line drive.
"Those are hard ones to judge where they're going to end up. If he barrels that, it's a lot farther. Fortunately for me, I was able to correct myself in time to catch it, so it worked out.
"My heart jumped, for sure. It calmed down after I realized I caught it. It was good though. It's one of those where you realize, if I can catch that one, I can catch about any of them. So I got it out of the way early."
One of the tough things about converting to the outfield is that a player can go several games barely being tested, then get several critical plays at once with a game on the line. Ackley has played outfield enough in his past to understand the position, but is soaking up as much action as he can to get comfortable now.
"It's just the more reps you can get," he said. "Batting practice helps a lot, taking balls out there. You can't really simulate the balls like last night, the line drives, but you've just got to keep taking balls in BP and get the best reads you can and learn how the ball carries here.
"Compared to second base, the ball looks so small out there. It looks like a golf ball. It's definitely different, but it's going alright. Nothing crazy."
Greg Johns is a reporter for MLB.com. Follow him on Twitter @GregJohnsMLB as well as his Mariners Musings blog. This story was not subject to the approval of Major League Baseball or its clubs.