The 22-year-old was batting .309/.393/.507 through 152 at-bats and had mastered the double-play pivot with Double-A Trenton when misfortune struck.
A right ankle injury shelved Adams in late May, and he has not returned to Trenton since. Originally diagnosed with a bone bruise in his ankle, Adams later had surgery to remove small bone chips.
He felt encouraged in spring training last year that he was ready to resume playing regularly, but his ankle didn't respond. Adams spent most of last season rehabbing the injury, reaching high Class A Tampa for 12 games late in the summer.
Now 24, Adams said this spring that he felt happy about his progress. During the early part of spring training, the 6-foot-1, 202-pound second baseman was playing four innings every other day.
"It's not 100 percent, but I am making progress and it feels good," said Adams, a third-round pick in 2008 from Virginia.
Adams said that he also had endured plantar fasciitis, tendinitis and some arthritis in the ankle. He estimated in early March that the ankle was 85 percent healthy.
Even while sidelined in 2010, Adams still intrigued the Mariners enough that Seattle asked that he be included in a proposed deal for Cliff Lee.
While that deal fell apart, Adams was more troubled by his slow rehab than the lost opportunity to ride a faster track to the big leagues with the Mariners.
"It was tough knowing this is the game I love and a career I want to spend my life in," Adams said. "I tried to keep a smile on my face and cheer for the other guys, but it was tough knowing that I could be out there."
Adams credited his wife Camille with helping him through the tedious rehab process and not being able to play.
"She has helped me mentally to stay focused and stay positive," Adams said. "You get away from something you love for so long it's definitely good having your wife there for support."
• Catcher Austin Romine missed the beginning of spring training exhibition games with inflammation in his back early in camp.
• A shoulder problem kept Rule 5 pick Brad Meyers out of action early in the exhibition schedule. He finished last season with the Nationals' Triple-A Syracuse affiliate.