But there he was Sunday, still a few weeks from his 23rd birthday, taking hacks in the batting cage at Yankee Stadium and getting a good ribbing from his excitable teammate Dustin Pedroia.
"I think it really hasn't hit me yet until my name is called," Bradley said, "then I'm pretty sure I'll go numb a little bit."
The Red Sox had intended to start Bradley in the minor leagues this season but their thinking began to change about halfway through camp. The spot then became open because David Ortiz and Stephen Drew are injured.
To make room for Bradley on the 40-man roster, infielder Mauro Gomez was designated for assignment.
Boston also placed pitchers Craig Breslow (left shoulder tendinitis) and Franklin Morales (lower back strain) on the 15-day DL, both retroactive to March 22.
Mariners keep Bay
Jason Bay found himself in unfamiliar territory, competing for a big league job, and then landed on the Seattle Mariners' opening-day roster.
Despite all the injuries and struggles, the outfielder still believes he can contribute at this level.
The Seattle Mariners designated outfielder Casper Wells for assignment Sunday and kept Bay as the club's fifth outfielder, finalizing their 25-man active roster ahead of Monday night's opener against the Oakland Athletics.
"It was kind of the first time I've really had to make the team," Bay said Sunday before the Mariners went through an informal workout. "I actually kind of liked it. It was different but I never really thought otherwise. I've been comfortable with myself and what I've done. From the day I signed here, I was on the team in my own mind, and I still had to go out and hear that, and I'm glad that I did."
Bay is thrilled to begin anew after three injury-plagued seasons with the New York Mets.
He is ready to prove himself again in whatever his role becomes.
"I had chances to go elsewhere and I'd probably get more playing time but I wasn't really doing this to boost value for next year," he said. "I was doing it to have fun this year, in whatever capacity that might be, if I have 200 at-bats or 600 at-bats."
After signing a $66 million, four-year deal before the 2010 season, the three-time All-Star hit .234 with 26 homers and 124 RBIs over the past three years, including a .165 average with eight homers and 20 RBIs in 2012. He sustained concussions and rib injuries and was limited to 288 total games with the Mets. The sides agreed to terminate his contract.