Raul Ibanez was selected as a finalist in the Top Moment category for his 29th home run of the year, which tied Ted Williams' record for most homers in a season by a player age 40 or older.
The other Seattle finalist is Dustin Ackley, for Top Defensive Play after his sliding catch at the base of the wall in Houston in Taijuan Walker's debut game.
Major League Baseball's A-listers will take home 2013 GIBBY trophies -- the ultimate honors of the industry's awards season -- based on votes by media, front-office personnel, MLB alumni, fans at MLB.com and the Society for American Baseball Research.
This year's GIBBY Awards include individual honors for MLB MVP, best starting pitcher, hitter, closer, setup man, rookie, breakout hitter, breakout pitcher, comeback player, defensive player, manager, executive and postseason performer.
GIBBY trophies also will be awarded for the year's top play, storyline, hitting performance, pitching performance, oddity, walk-off, Cut4 topic, regular-season moment and postseason moment, from MLB.com's Must C highlight reels.
In the past five years, fans have cast more than 50 million votes across the various GIBBY categories, none of which was restricted to individual League affiliation. Fan voting runs through Dec. 1.
Winners will be presented their GIBBY trophies at the MLB.com Greatness in Baseball Yearly Awards extravaganza during the Winter Meetings in Orlando, Fla.
Iwakuma was outstanding in his first full season as a starter in the Majors, as the 32-year-old earned his first American League All-Star berth and went 14-6 with a 2.66 ERA. The former Japanese star finished second in the AL in WHIP with a club-record 1.006; third in ERA, innings (219 2/3) and opponent's batting average (.220); fourth in strikeouts-to-walks ratio (4.40) and quality starts (23); fifth in opponent's OPS (.630); and 12th in strikeouts (185).
"He's special," Mariners third baseman Kyle Seager said. "Ever since he became a regular starter, he's been one of the best pitchers in the game. You get guys coming to third base all the time talking about how nasty he is and how the ball's moving all over the place and you can't get a good swing on him. That's about as good a compliment as you can get."
Iwakuma will compete for Starting Pitcher honors with Max Scherzer and Anibal Sanchez of the Tigers, Bartolo Colon of the A's, Yu Darvish of the Rangers, Jordan Zimmermann of the Nationals, Cliff Lee of the Phillies, Matt Harvey of the Mets, Jose Fernandez of the Marlins, Adam Wainwright of the Cardinals, Madison Bumgarner of the Giants and Clayton Kershaw of the Dodgers.
Breakout Pitcher finalists also include Chris Tillman of the Orioles, Koji Uehara of the Red Sox, Mike Minor of the Braves, Travis Wood of the Cubs, Patrick Corbin of the D-backs, Andrew Cashner of the Padres and the Mets' Harvey, the only other pitcher selected for both awards.
Among the competition for Ibanez's top moment are Ichiro Suzuki's 4,000th hit for the Yankees, Yasiel Puig's debut with the Dodgers, the emotional night at Fenway Park following the Boston Marathon bombing, Bryce Harper's Opening Day heroics for the Nats and Todd Helton's home finale for the Rockies.
Ibanez, 41, slowed in the second half of the season after hitting 24 home runs by the All-Star break, but he finally tied Williams' record with a solo shot in the ninth inning of a 6-5 loss at Anaheim on Sept. 21. Williams hit 29 home runs at age 41 for the Red Sox in 1960.
"I feel fortunate to be in this situation," Ibanez said after his historic homer, which also happened to be the 300th of his career. "Any time you're in the company of the great Ted Williams -- I read his book when I was in high school, and this was the greatest hitter that ever lived. To have this one thing -- and make no mistake, it's just this one thing -- that I have in common, it's a great blessing."
Ackley's gem Aug. 30 was one of 30 selected to compete for the Top Defensive Play, with one from each team in the Majors. The center fielder went deep into the right-center gap with a long run before hauling in Robbie Grossman's drive with a sliding catch to preserve Walker's career-opening victory at Minute Maid Park.
"Man, the catch was pretty fun; I'll have to say that," Ackley said at the time, just in the beginning process of transitioning from second base. "I haven't really had many plays like that, so that was pretty sweet."
And now it's one of the GIBBY finalists, alongside a host of top players and moments from 2013 in the Major Leagues.