NEW YORK -- When the Yankees traded Jesus Montero for Michael Pineda in January 2012, Yankees GM Brian Cashman made a statement that was both audacious and puzzling.

“He may well be the best player I’ve ever traded," Cashman said.

Coming from a man who had already dealt away Randy Johnson, Alfonso Soriano, Ian Kennedy, Kenny Lofton, David Justice and Austin Jackson, it was a bold and striking thing to say.

It also turned out to be dead wrong.

Pineda, who has yet to throw a pitch in the big leagues for the Yankees, having been sidelined with serious shoulder surgery in his first spring training with the club, remains a player with a promising, if uncertain, future and is still considered by many to be on the way up.

But after a tumultuous two seasons as a Seattle Mariner, the 24-year-old Montero might already be on his way down.

“If he [makes the team], great," Seattle GM Jack Zduriencik told MLB.com in December. "Great for Jesus Montero, great for this organization. But at this time, if you are bringing him in here and counting on him, I think that's a little too risky at this point. I think you’d be foolish to say you were counting on this guy."

It may be hard to believe now, but just a little more than two years ago, the Yankees were counting on Jesus Montero to develop into the latest in a line of catchers who were also offensive powerhouses, a line that ran from Bill Dickey to Jorge Posada, passing through Hall of Famers Yogi Berra and Elston Howard along the way.

"This was a tough deal, a very tough deal," Cashman said on a conference call with reporters on the Monday evening after the trade. “I believe he's a middle-of-the-lineup-type bat and very gifted. He's a good kid and he's going to have a heck of a career, he really is."

While Pineda broke down in March 2012, Montero performed acceptably for a rookie in his first season as a Mariner, hitting 15 home runs and driving in 62 runs while batting .260 in 135 games. But in 2013, Montero fell off the cliff, hitting just .208 with three home runs and nine RBIs before being demoted to Triple-A after just 29 games.

From there, it only got worse. The Mariners, apparently abandoning hope that Montero would ever develop into a full-time major league catcher -- at one point, he went 0-for-35 trying to throw out base stealers -- begin trying to convert him to a first baseman. He continued to struggle at the plate, batting just .247 with a home run and nine RBIs in Triple-A. That experiment was cut short when Montero suffered a torn meniscus, requiring season-ending surgery.

Then, he was put down for 50 games by MLB in connection with the Biogenesis investigation. He capped off his annus horribilis by suffering a hand injury in a car accident that cut short his season in the Venezuelan Winter League.

If nothing else, Montero should serve as a cautionary tale. Practically overnight, he went from “can’t miss" to can’t hit. Or catch.

“He was highly touted by everyone throughout the industry," Cashman said. “I think the entire industry looked at Jesus Montero and said, this guy’s got monster right-handed power and he did, but that doesn’t guarantee anything."

But apparently, not everyone in baseball was as high on the Venezuelan-born Montero as the Yankees, who signed him for $1.6 million in 2006.

“Everyone knew he couldn’t catch,” one scout told ESPNNewYork.com. “He didn’t stop hitting until he got to Seattle.”

Cashman, who right up until the time of the Pineda trade continued to maintain he expected Montero to someday become the Yankees’ everyday catcher, now says Montero’s 6-3, 230-pound frame was an impediment to his development.

“It’s difficult [to be a catcher] when you’re that big," Cashman said. “Physically he’s capable. He’s got a great arm. But he has a long release because of his size."

But a baseball insider told ESPNNewYork.com there were other factors besides size working against Montero. “I’ve heard rumblings that he’s a little bit of a [diva], and he’s lazy over there," the source said. “I hear King Felix [Hernandez] hates throwing to him, and that he’s cocky way beyond his accomplishments. Hey, he’s been written up as this great cover boy and so maybe that went to his head and he doesn’t work as hard. I don’t know."

This spring, Montero comes to Mariners camp no longer as the up-and-coming phenom, but as just another farmhand trying to earn a spot on one of the least-successful teams in baseball.

"You know he's a talented player, but he does have [minor league] options, he's switching positions and I think at this moment in time you can't necessarily count on him," Zduriencik said. “I'm not saying he won't come in and be ready to roll and all of the sudden you are looking at the Jesus Montero you thought you acquired, but he’s been through too much the last year and he has too much to prove to all of us.

“It’s all up to Jesus," Zduruencik said. "This is a golden opportunity for him and it's laid right in front of him. How he handles, well, it's in his lap."