Smallwood committed to USC in February of his junior year, and now feels the decision may have been rushed.
"My commitment got soft on them," Smallwood said." Basically I made that decision really early and I need to keep looking."
The 6-foot-1, 285-pound defensive tackle plans to take an official visit to USC, but will take all five before making a decision.
He has not set dates for his visits and said some will come after the season.
"I feel like USC is a good program, especially for the type of major I want to be," Smallwood said. "I feel like they've got a good business program. That's the main thing I'm focused on – education. USC football is obviously great too. I could be very successful there."
"I'm not deciding 100 percent until after I take all my officials," Smallwood said.
Ranked as the No. 18 defensive tackle in the 2014 class, Smallwood sat out his game Friday night with a knee injury, but will return to action next week.
His official visits, he said, will all take place during off weeks or after the end of Central's season. The four schools behind USC even in his top five.
"Oklahoma is a place I've been looking at since the beginning," Smallwood said. "I like coach [Bob] Stoops. He's a good guy and runs a great program."
Arizona State, Smallwood said, is of interest because of his potential role in the defense.
"At Arizona State, I like the defensive scheme that they run," he said. "I feel like it fits me and kind of highlights what I can do on the field."
Relationships will be a key part of Smallwood's decision and two of the strongest come from in-state options.
"With UCLA and Cal, it's both the coaches," he said. "I have a great relationship with the coaches for both of those schools. I like the coaches and I'm excited to visit both of them."