The jewel centerpieces of the deal were highly touted.
Montero, a smooth-hitting catcher, had come up through the Yankees' system, hit four home runs and batted .328 in a 61 at-bat big league debut at the end of 2011, and become one of the top offensive prospects in baseball.
Pineda, a hulking, 6-foot-7, hard-throwing starter from the Dominican Republic who had made the All-Star team in his rookie year with Seattle at the age of 22, finishing fifth in American League Rookie of the Year Award voting after posting a 3.74 ERA and striking out 173 batters in 171 innings.
It was a blockbuster of sorts as a result, with the pitching-keen Yankees and offense-starved Mariners a perfect match for each other and observers of the game intrigued by what the future might hold for each player in a new organization.
It was nothing but positive vibes for both players and both clubs -- one of those "good old-fashioned baseball trades" that should yield dividends everywhere in due time.
But it hasn't happened that way at all. Baseball, and life in general, took over, and Spring Training 2014 has brought to light a very different reality for Pineda and Montero.
For Montero, the struggles started with his defense. Despite scouting reports that predicted he'd never be a good Major League catcher, Montero, then 22, was committed to improving behind the plate and the Mariners gave him that opportunity in 2012. He started 55 games at catcher, was the designated hitter in 78 games, and got 515 at-bats. Montero hit 15 homers and drove in 62 runs, but despite a decent .260 batting average, his on-base plus slugging was only .685.
The Mariners drafted catcher Mike Zunino with their first pick that summer, a signal that Montero's days as a catcher were numbered.
Montero didn't help himself in 2013. He struggled at the plate and behind it at the beginning of the season and was optioned to Triple-A Tacoma, where he began transitioning to first base, injured his knee and ended up being suspended for the final 50 games of the season because of his involvement in the Biogenesis scandal.
Over the winter, Montero played first base in the winter league in his home country of Venezuela but suffered a lacerated right hand in a car accident, and then, by his own admission, was careless with his diet and came into this year's Spring Training in Peoria, Ariz., well overweight.
The luster from the big trade has worn off, and Montero is up against it in a tough camp, with Justin Smoak and Logan Morrison also figuring to get playing time at first.
"He has a lot of work to do," Seattle manager Lloyd McClendon said. "To his credit, he's putting the time in. So we'll see. My eyes are wide open when it comes to Montero. I'm not closing any doors and I'm not opening any doors. It's all going to be up to him.
"I see a young man that still has a chance. I can't want it for him. At some point, the light has to come on for all of us. In my talk with him, he's at a crossroad. It's time to either put up or shut up. So we'll see where we are."
Montero sounds like a man who realizes that he has a lot to prove in a short time.
"I feel great, I just have to go through Spring Training and see what happens," Montero said. "I have an opportunity again, and I hope to do well and help my team to win. This is a big year for me to get my confidence again and prove I can play in the big leagues."
Over in the Grapefruit League, getting ready to suit up in pinstripes, is Pineda, who looked so good for the Mariners in 2011 but still hasn't pitched a Major League inning for the Yanks.
Amid all the excitement of the much-publicized trade, Pineda didn't stay in shape and reported to Tampa, Fla., for Spring Training two years ago about 20 pounds overweight. He wasn't throwing nearly as hard as he did in Seattle, and by April, he needed surgery to repair a tear in his shoulder.
"It just wasn't coming out like we saw during the middle of the  season," Yankees manager Joe Girardi said. "For a power guy, early on in Spring Training, you're not too worried about it, because it takes time. But it just never increased much."
The big man has come all the way back now. Pineda looked good in a brief Minor League stint after making it back to the mound last year, and he's looked good this spring.
"I can tell you, his stuff's a lot closer than it was to when we got him ... a couple of years ago," Girardi said.
Maybe Pineda will be able to pitch his way into a Yanks rotation that would welcome a version of his former self. Maybe he'll be the first one from that fading January 2012 trade to truly impact the big leagues for years to come, a scenario that was predicted for both players.
Once again, the baseball world will find out.
"I'm so excited. [The surgery] was a long time ago," Pineda said. "I've been practicing, working hard, so now I feel ready to go. I feel very excited about it."