That means that in just more than one year, Chamberlain progressed through every level of New York's Minor League system and finds himself on the active roster of one of the most revered franchises in professional sports.
"I'm ready to explode," Chamberlain said. "I'm ready to get out there and play catch. Put [the uniform] on and go to work. That's what we're all here for, and that's what we work so hard for. I can't wait for the opportunity to get on the mound and finally let it go."
Entering this season, Baseball America ranked Chamberlain as the Yankees' fourth-best prospect, but no one could have foreseen just how quickly the young right-hander would rise to the Major Leagues. But that's what will happen when anyone compiles a 9-2 record with a 2.45 ERA while striking out 135 batters in 88 1/3 innings.
Yankees roving pitching coordinator Nardi Contreras said he first got the impression that Chamberlain might rise through the ranks quickly when he saw him open the season with Class A Tampa.
"He's like a man among boys when it comes to his stuff and being able to do the things that he's capable of doing, and does," Contreras said.
Chamberlain's impressive Minor League numbers, and his quick rise to the top, means that a lot will be expected of him now that he's in pinstripes. Making things even tougher on the young fireballer is that until last week, he spent his entire career as a starting pitcher.
Yankees manager Joe Torre said his club will be closely monitoring Chamberlain's arm strength. At least for now, the righty will be brought in only to start an inning, and he's not expected to pitch on back-to-back days. That doesn't mean there won't be a lot of pressure on the young hurler, though.
Torre is excited to see Chamberlain pitch, but he also wants everyone to remember how little experience he has under his belt.
"You've heard so many positive things about him," Torre said. "We just have to make sure that we understand how old he is, how much experience he has, and go accordingly from there."
In anticipation of a big-league callup, Chamberlain had a conversation with Jason Giambi on what it takes to get Major League hitters out while the Yankees slugger was rehabbing with Triple-A Scranton/Wilkes-Barre.
"He's been around the game," Chamberlain said. "Young guy coming up, first time in this situation, for me to understand what [hitters] look for and how they recognize pitches is just going to make me better. [That] I can take it and use it in the game and understand how they recognize pitches is just going to make me better."
At the start of the season, who would have thought Chamberlain would be looking for that kind of advice? A lot has happened over the last 12 months.
"There are times where I wake up and have to realize where I'm at," Chamberlain said. "That's the great thing about it. Learning on the job is the best way to do it. I'm excited to be here and ready to go out there and do the best I can to help us win."
To make room for Chamberlain on the active roster, New York optioned right-hander Brian Bruney to Triple-A. Bruney was 2-1 with a 3.40 ERA in 42 1/3 innings out of the Yankees' bullpen.
Rivera keeps rollin': Yankees closer Mariano Rivera just keeps getting better as the season rolls along. Rivera picked up his 18th consecutive save of the season on Monday afternoon against Toronto. After blowing his first two save opportunities of the season, Rivera is 1-1 with a 1.32 ERA.
His 431 career saves are the second most of any active Major League reliever, trailing only San Diego's Trevor Hoffman. In his latest outing against Toronto, Rivera was simply dominant. Protecting a slim one-run lead and facing the heart of the Blue Jays' lineup, Rivera needed just 16 pitches to help lead the Yankees to their fourth straight victory.
Coming up: Chien-Ming Wang (13-5, 3.49 ERA) is scheduled to take the mound for New York when the Yankees close out a three-game series against the Blue Jays at 7:07 p.m. ET on Wednesday night at Rogers Centre. Toronto will counter with ace Roy Halladay (12-5, 4.13 ERA).