By Ryan Divish

The Seattle Times

ARLINGTON, Texas — It’s been a season of transition for Reggie McClain. A starter for much of his college and pro career, he was asked to become a full-time reliever this season. That switch allowed him to climb the organizational ladder at a unique pace, going from High-A to Class AA to Class AAA and now the big leagues in the span of one season.

Despite that meteoric rise through the system, McClain knows he’s far from a finished product. He’s still trying to develop the routines of a reliever in his daily workouts, throwing sessions, warm-up plan and in-game mindset.

“It’s a bunch of things that go into it,” he said. “I’m trying to find the best version of me.”

His numbers reflect that transition. An 0-1 record with a 4.15 ERA and a blown save in seven appearances isn’t eye-popping. But the Mariners have been pleasantly surprised with McClain and how his power sinker has played at the MLB level. You have to look a little deeper at his usage to see their optimism. He gave up three runs in one inning in his MLB debut against the Astros, which is understandable.

Over his next four outings, he pitched 8 2/3 innings, allowing just one run on five hits with three walks and three strikeouts. His last two outings showcased the good and bad. He struggled in Toronto, allowing a run on two hits and a walk. He came back with three innings against the Yankees’ potent lineup, allowing just one run on three hits with four strikeouts. Of his outs registered in 13 innings, 59 percent have come on ground balls, which is a good thing in this new era of launch angle and lifting the ball.

“He’s been very effective,” Mariners manager Scott Servais said. “He’s done a lot of good things and opened some eyes here. It’s been quite a season for him from where he started at to where he is now.”

Servais has one quibble: McClain has allowed a walk to the first batter he’s faced in three of his last four outings and four of his last seven. It seems to take a batter or two for McClain’s sinker to really get moving.

“I’ve often said that the first hitter a reliever faces, it’s probably the most critical, whether he’s starting an inning or coming in with a runner on base, it’s huge to have your best stuff right out of the chute,” Servais said. “You won’t have it every night, but you’d like to see it happen more times than not. He needs to figure something out. It could be related to his warm-up program and how he’s doing it, but I’ve talked to Jim about it and he said he’s letting it go and letting it eat before he gets in there.”

McClain is aware of the issue. He doesn’t think it’s related to his warm-up routine.

“I think with the first couple of batters I’ve fallen into the trap of trying to get a feel in the game instead of just coming out and firing,” he said. “It’s something I’m adjusting to being in the bullpen, coming out and having that stuff that I probably have later in the game to that first batter.”

The process of thinking like a reliever is still not ingrained into him.

“I think it’s more mindset,” he said. “I’m doing everything to prepare to go into the game. But the mindset needs to be attack rather than trying to get feel for everything and get a feel for the game. It’s kind of not the place to do that out of the bullpen. That first guy is usually the most important. I’m working on it.”

Seven heading to AFL

The rosters for the prestigious Arizona Fall League have been announced and the Mariners will be sending seven players and one coach to the Peoria Javelinas.

As expected, the Mariners’ top two outfield prospects Jarred Kelenic (No. 1 overall) and Julio Rodriguez (No. 3) headline their selections.

Joining them will be infielders Joe Rizzo (No. 20) and Jose Caballero, who was acquired from the Diamondbacks in the trade for Mike Leake.

The Mariners will send three relievers to the AFL, lefty Aaron Fletcher (No. 27), who was acquired from the Nats at the trade deadline, hard-throwing reliever Raymond Kerr and right-handed reliever Sam Delaplane.

Carson Vitale, the Mariners minor league field coordinator, will serve as an assistant coach on the staff.

The schedule for the AFL was bumped up this season to get rid of the layoff after the minor league teams get done playing Sept. 2. The AFL will begin on Sept. 18 and conclude on Oct. 26.