But Armstead, ranked No. 1 by Scout.com in the Class of 2012, continued to draw interest from colleges so, this past weekend, he decided to decommit from the Trojans and open up his recruitment.
"When I committed to USC, I felt it was the best fit for me, and I loved it there. But I have to find what's best for me and get out there and see some other schools."
Armstead plans to visit Notre Dame next weekend and Alabama the first weekend of November, when the Tide hosts LSU. Armstead said he is heavily considering the Irish and Tide but is looking at other schools, too.
"I'm going to look at Cal, Michigan and some other new schools that I'm sure will come on now that I've decommitted," he said.
Where his three remaining trips take him remains to be seen.
"I have to sit down and see my season schedule," he said, "but nothing is set in stone right now."
Armstead said the early commitment to USC and the subsequent rise in his stock — new schools showed interest in him — have made him rethink things.
"I owe it to myself to get out there and see what else is out there, so these trips will help me a lot," Armstead said. "I committed a long time ago, and now I want to take the time to make the best decision for myself."
The five-star offensive tackle wants to play on the defensive line in college, and that played a big role in his recruitment, as well.
"It's a big factor, wherever I go, that I want to play defense," he said. "So schools recruiting me for offense, they can do that, but they'll be hard to consider."
Schools also will have to consider his interest in basketball: Armstead is one of the top big men in the basketball class of 2012.
"The biggest part of my decision is to balance football and hoops," Armstead said. "Any school that won't consider me as a basketball player, I won't consider them."
Another factor in Armstead's decision to reconsider his commitment to USC stemmed from his brother's treatment there. His brother, Armond, has been at USC the past four seasons, but he has been sidelined in 2011 because of a medical issue and has yet to play a down for the Trojans.
"I've been disappointed with the way some of the things have been handled with the school and my family over the last six months," Armstead said.
That doesn't mean he won't still end up at USC, however.
"I'm still considering USC," Armstead said. "I still talk with the coaches, and have good relationships and that won't go away."
But for now, he'll re-enter the recruiting cycle.
"I've felt like this was going to happen for the last month or so," Armstead said. "Distance won't be a factor for me. I want to get out there and see what cities I can live in, get a good feel for the campus."
Armstead would like to make a decision before National Signing Day.
"There really is no timeline," he said, "but I plan on graduating early, so if I can somehow make a good decision within that time frame, I will. But if I need to take a little more time, then I will.
"I'm still taking classes like I'm going to graduate in December."
Armstead will play in the U.S. Army All-American Bowl in San Antonio in January.