ARLINGTON - When veteran George Sherrill underwent season-ending elbow surgery in April, there was some uncertainty over where the Mariners stood with left-handed relief help. But Rule 5 rookie Lucas Luetge has more than answered that question in the season's first two months.

Luetge has yet to allow an earned run in 18 appearances, shattering the club record of 14 scoreless outings to open a career. Going into Wednesday's series finale with the Rangers, he'd held opposing left-handed hitters to a .083 batting average (2-for-24) with 12 strikeouts.

Charlie Furbush, acquired in the Doug Fister deal last year, has been very effective as well as Seattle's other left-hander in the bullpen. Lefties are batting .138 (4-for-29) against him with 15 strikeouts.

Luetge has stranded 12-of-13 inherited runners, with Furbush at 10-of-15.

Luetge, who has had about 15 family members travel from his hometown of Industry, Texas, for each of the games against the Rangers, said he's growing more and more comfortable as a strict lefty specialist after throwing in a variety of roles coming up in the Brewers system.

"Last year there'd be like two weeks where I'd be strictly throwing to one batter or so, then I'd be long relief," said Luetge. "The Minor leagues are a little different because they want to see what all you can do. So I've never done it for this long a period, but heck, I like it. I go out there and I either get the guy out and it's a really good day, or I don't and it's a really bad day."

Luetge said the biggest adjustment has been learning to not throw too many warmup pitches, since a lefty specialist can be asked to get up in the bullpen several times in a game and then needed the next day as well. But manager Eric Wedge indicated the 25-year-old could see an increased role as the season advances.

"I want to do more with Luetge," Wedge said. "We've used Furbush for more than one hitter and as a multiple-innings guy, but I want to use Luetge more than just a straight one-matchup guy, just for his own development up here, too. I think he'll do a fine job. It's just the way it's worked out for us so far."

Mariners option Delabar to Triple-A

ARLINGTON -- Right-handed reliever Steve Delabar was optioned by the Mariners to Triple-A Tacoma following Wednesday's 21-8 victory over the Rangers, opening a roster spot that won't be filled until before their next game Friday in Chicago.

The expectation is that right-handed reliever Stephen Pryor will be recalled from Tacoma, but the Mariners didn't make any official announcement on Wednesday. Pryor has yet to allow a run in 12 innings over nine appearances for the Rainiers, with two saves.

Pryor, 22, has only allowed five hits with seven walks and 15 strikeouts in his 12 innings since being promoted to Tacoma. He was 1-0 with a 1.13 ERA in Double-A Jackson with seven saves, allowing just two earned runs in 16 innings.

He was a fifth-round Draft pick in 2010 and split last season between Class A High Desert and Jackson.

Delabar, 28, is 1-1 with a 5.18 ERA in a team-high 25 relief appearances for the Mariners. Opponents have hit just .200 against the hard-throwing reliever, but seven of his 18 hits allowed have been home runs.

Delabar made his Major League debut with the Mariners last season after beginning the year as a substitute teacher and high school coach in Kentucky, rising quickly through the system with a strong campaign that ended with his September callup.

He then made this year's team out of Spring Training and has thrown 24 1/3 innings with 18 hits, seven walks and 31 strikeouts. His 25 appearances is tied for the third-most among American League relievers.

Worth noting

• Dustin Ackley has excelled in bases-loaded situations in his brief career. The Mariners second baseman had a bases-loaded single in Tuesday's 10-3 victory over Texas and is now 4-for-5 with six RBIs in that situation this season and 8-for-10 with 14 RBIs in his career.

• Ichiro Suzuki recorded nine putouts on Tuesday, which is the second-most by a right fielder in Mariners history for a nine-inning game. Ichiro set the club record with 10 putouts on May 2 at Tampa Bay, which broke his own record of eight.

The franchise record for most putouts by any outfielder is 11 by Ken Griffey Jr.

• Outfielder Casper Wells went 1-for-3 with a double and two walks in Double-A Tacoma's 13-5 loss to Reno and is hitting .350 in six games (7-for-20) with a home run and four doubles since being sent down by the Mariners.