The Mariners have almost set their opening day roster, and Daniel Robertson may be on it. As David covered, this is surprising. Robertson was acquired in November, after the Angels decided they didn't want him. Soon, the Mariners didn't want him that much either, and designated him for assignment. They felt bad, and Jerry invited him to spring training, and against all odds, he might make this team. If he does, you will probably forget about it soon after, just as you forgot that the following seven M's were on the opening day lineup card at some point during the Jack Zduriencik era.
2015—Tyler Olson: 2015 is the hard one here. It was just last year! Who am I supposed to say, Rickie Weeks? Like you don't remember Rickie Weeks, the super-sub signing of the off-season, turned Ball-Dropper of Left Field.
You can be forgiven for forgetting Olson, however. He was only here for eleven games, he walked a lot of people, mostly pitched badly, set a few big league records, and then was dispatched to Tacoma for four months. To the extent he is remembered, he'll be recalled much as we imagine the 2015 Mariners themselves: initially promising, ultimately disappointing, and silly enough in hindsight that we'll all wonder how we ever imagined it would work.
2014—Hector Noesi: Look, there aren't going to be a lot of good players on this list; good players tend to be very memorable. Noesi is too, unfortunately, although most of our collective resentment dates back to 2012. He was also bad in 2013, and then for two games in 2014. He was only on the big league roster for five days in 2014, and he gets a mention here for timing those five days spectacularly well for the purpose at hand. After allowing a walk off to Coco Crisp in the infamous Barber Game, he was finally DFA'd.
2013—Robert Andino: There are too many candidates here. I think we've all tried to wipe the 2013 season from our memories, as it represented the low point in Jack Z's dingers-'n-dingers player acquisition strategy: Raul Ibanez and Michael Morse were given gloves. Jason Bay pinch ran regularly and occasionally stood in center field. Jeremy Bonderman made seven starts. Bleak times best forgotten.
The Mariners did win on opening day that year though, because they always do, and the team that day featured an odd cast of characters. Kelly Shoppach! Lucas Luetge! Kameron Loe! I probably should have picked Loe instead of Andino, although I'm sure you've forgotten all 14 of his base hits by this point. I can't believe he batted 85 times.
2012—George Sherrill: Sherrill never actually made it to Seattle: his first outing was a stinker in Japan, his second a clunker in Texas. His velocity was down, his location was a mess, and it was no surprise when we learned that his elbow wasn't entirely right. He did manage to post a 24.84 FIP, which is something I've never encountered before.
2011—Adam Moore: One of my favorite baseball facts is that Moore has appeared in a big league contest in each of the past five seasons while only appearing in 21 games total. In 2011, he banjaxed his knee in the sixth (his second) game of the season in what was ultimately his last act as a Mariner.
2010—Kanekoa Texeira: The platonic ideal of this post, Texeira was rule-5 pick who hung around for 18 innings before hitting waivers and packing for Kansas City. I've always admired Texeira, for four reasons. First, he showed a lot of understandable and relatable emotion while working in and out of trouble in his big league debut. Second, his surname is spelled slightly differently than Mark Teixeira's, which is good for the soul and the copy editor within. Third, he escaped the 2010 Mariners, a feat I was unable to replicate. Fourth, he threw me a ball once. Thanks Kanekoa.
2009—Wladimir Balentien: This one is surprising because Balentien is not the type of player who feels like a guy who would wind up on a big league roster. You know? He's in a category with Carlos Peguero, Mike Wilson, Alex Liddi, Luis Jimenez, and too many other one-dimensional Mariners who were talented enough to get a shot, but not good enough to design a plan around.
There was a plan for Balentien, however, even if the plan was "keep Wladimir Balentien off the field as much as possible." He was on the roster for four months, but came to the plate only 170 largely forgettable times. Before embarking on a successful career overseas, he had one more preposterously long home run to hit for Cincinnati; you should really take time to watch it, if just to make sure that it's not about to land on your head.