Granderson was drilled by a fastball from Blue Jays left-hander J.A. Happ in the first inning of New York's 2-0 Grapefruit League loss on Sunday at George M. Steinbrenner Field. X-rays taken by Dr. Daniel Murphy in Tampa revealed the fracture.
"My body was feeling good, my arm was feeling good, ready to go," Granderson said. "Five pitches in, we've got a little setback. It could be worse, but now we rest, recover, get it back and get ready to play whenever that day comes."
Granderson returned to the stadium after getting the diagnosis wearing a soft form-fitting brace on his forearm. The injury is expected to keep the 31-year-old out of action at the big league level until early May.
That instantly added new questions to the Yanks' game plan, as the club planned to have a starting outfield of Granderson, Brett Gardner and Ichiro Suzuki in some alignment on Opening Day.
"We'll have to sit down and figure out what we're going to do," Yankees manager Joe Girardi said. "Grandy is not a bat that you easily replace, but we're going to have to find a way."
Granderson joins the list of power-hitting 2012 Yankees who will be absent from the Opening Day roster as the club aims to defend the American League East title while bracing to score fewer runs this season.
A group of seven players -- Granderson, Alex Rodriguez, Russell Martin (now with the Pirates), Raul Ibanez (now in Seattle), Nick Swisher (now in Cleveland), Eric Chavez (now with the D-backs) and Andruw Jones (now in Japan) -- were responsible for contributing 155 home runs to the Bombers' attack last season.
"We might have to score runs a little bit different way," Girardi said. "Every person's opportunity, a lot of times it's because of an injury. Sometimes you just kind of push your way through, but sometimes, it's because of an injury and someone gets to shine and ends up being there a long time."
Granderson's injury promises to create more spring playing time for non-roster invitees Matt Diaz and Juan Rivera, as well as young switch-hitter Zoilo Almonte. Girardi also mentioned the names of Melky Mesa and Adonis Garcia among his choices.
Yankees general manager Brian Cashman said that it is too soon to say how the team will proceed, considering exhibition games just started and pro scouts have had little time to look at internal and external options, but Diaz and Rivera figure to be high on the list of in-house choices.
"They're already guys competing for a spot on the club anyway," Cashman said. "That continues. We'll be forced to take a look at a short-term option at the same time. We'll obviously be getting Curtis back, just not until May."
Cashman said that he did not consider Eduardo Nunez, who played three games in left field for the club in 2012, as an outfield choice.
"Not necessarily for me, but it could be [an option] for other people," Cashman said. "I don't see that as something that is an option from my perspective."
The injury also abruptly ended the Yankees' experiment of having Granderson play left field in Spring Training, testing the waters of a position switch.
Granderson played just a half-inning in left field, and Girardi said that the injury likely cements that Gardner will be New York's Opening Day center fielder.
"Everything up to this point was all just trial, just to see how it's all going to be," Granderson said. "Who knows? When I come back it may be something they consider, or they may just scrap it and get me back ready to go the best, easiest way possible. The biggest priority is to come back."
Happ called the Yankees' clubhouse to check on Granderson after the plunking, according to Granderson, who said that it was "definitely nothing on purpose."
"He's trying to work and come inside, it's part of the game," Granderson said. "Pitches get thrown inside a lot. It's not going to be the first time, not going to be the last time."
In the meantime, Granderson said that he would try to keep a sunny outlook while he aims to rejoin the Bombers' lineup for the second month of the season.
"I've always had that mindset that you only can control what you can, and the situation is what it is right now," Granderson said. "To be down, pout, all of those things right now isn't going to change anything. We just continue to move forward.
"Obviously, it's a big bump in the road, but you move and keep your body ready to go, and mentally stay focused and ready to go. I'm always looking forward to the season, so that's not going to change. It just might be a little different start date, that's all."