It was one or the other.
Regardless, for the trade to be considered a success, right-handers Aumont and J.C. Ramirez and outfielder Tyson Gillies eventually must produce at the big league level.
Really produce, too.
"There's always expectations," Aumont said last week. "You give up somebody that big, a Cy Young winner ... I kind of prepare myself for that. I'm working hard every single day to be as good as I can be. I know that's what the Phillies want. And I want to prove to them that this wasn't a mistake."
Aumont, who already is in Clearwater, Fla., preparing for Spring Training, has the talent to make that happen. He is imposing at 6-foot-7. His fastball reaches the upper 90s.
MLB.com recently ranked him the 47th-best prospect in baseball.
A first-round pick in the 2007 First-Year Player Draft, Aumont worked as a starter in '08, but the Mariners moved him into the bullpen in '09 because they thought he could reach the big leagues more quickly as a reliever.
But the Phillies are returning him to the rotation in 2010 because they think he has a future as a starter.
"I don't have a preference," Aumont said. "Coming out of the bullpen last year, it fit my attitude in being aggressive. I learned a lot. I think going back to the rotation is going to be fine. I've tasted both. I have some experience now. Every fifth day, this is my day, this is what I have to do.
"Every single start is going to be a little bit easier for me than in 2008. I'm really looking forward to it. I'm going to be able to work on my pitches. I'm going to throw a lot of innings. The more I get, the more I'm happy, because when I'm on the mound, I'm in heaven. In my mind, I'm floating. This is the place that I want to be."
He is expected to open the season at Double-A Reading.
Aumont's own success will determine how quickly he reaches the Majors.
"One day, I want to wear that Phillies cap and play in Citizens Bank Park," he said. "I want to be part of this."
The Phillies are counting on it. They traded Lee to get Aumont, Gillies and Ramirez. They expect big things from them in the future.
Aumont expects big things from them, too.