The patience paid off.
Santos soaked up all he could from being around older teammates and spent extra time in the film room. When he stepped on the field against Michigan last Saturday, he didn't look like an ordinary first-time starter.
Santos made 10 tackles, including one for a loss, in the 21st-ranked Cornhuskers' 23-9 victory. Monday he was chosen one of the Big Ten's co-freshmen of the week.
"He can run, he's explosive, he can play in the open field and do some good things," coach Bo Pelini said. "Now he's at a point where he's not going to hurt us. He's really helping us and doing some good things. He's nowhere near where I think he'll be in the future, but he's getting better."
Pelini's defensive system is not easy for young players to grasp, and Santos had to put in his time. Santos didn't even play in the opener against Southern Mississippi.
The timetable for Santos was accelerated after Zaire Anderson went out with a knee injury in mid-September. Santos played some against Wisconsin and Ohio State but didn't really emerge until Oct. 20 against Northwestern.
He made three tackles against the Wildcats, including his first behind the line of scrimmage when he broke through and threw Kain Colter for a 2-yard loss.
Pelini deemed Santos ready to be a starting linebacker alongside Will Compton when the Huskers opened in their nickel package against Michigan.
"He's starting to make that push to being the guy we thought he could be," defensive coordinator John Papuchis said.
With his playmaking ability on the perimeter, the 6-foot, 220-pound Santos is a perfect fit for the Huskers when they go against mobile quarterbacks and spread offenses.
Nebraska (6-2, 3-1 Big Ten) will see more of a pro-set offense at Michigan State (5-4, 2-3) this week, meaning the Huskers probably will employ more of their 4-3 base alignment.
"I'm not really sure where I'll be at," Santos said, "but I feel like I might get a couple snaps during the game."
Given how productive Santos can be, it's difficult to imagine him being off the field for long stretches.
Asked what differentiates Santos from other Nebraska linebackers, senior Alonzo Whaley said, "He's just quicker."
"He's a smaller guy. He'll pursue to the ball. I don't want to say he gives us something another linebacker doesn't. He has (a nose) for the ball just like guys you've seen in the past. He does a good job pursuing the ball."
Whaley has taken Santos under his wing in the linebackers' meeting room. Whaley likes to give him advice and answer his questions. Whaley said Santos' humility is refreshing.
"He's good, quiet, willing to learn, takes notes," Whaley said. "He's in that stage where he's trying to consume everything. He asks questions.
"You have to respect a guy like that who doesn't get above himself because he got a lot of playing time. The name of the game is that you can never learn too much, and he understands that at a young age. That makes his future a lot brighter."
Santos was ranked among the nation's top 15 outside linebackers by Rivals.com when he was coming out of Klein Collins High School in Spring, Texas. Rivals also had him ranked among the top 40 overall players in the Lone Star state.
Arkansas, Kansas and Utah offered scholarships, but Santos picked Nebraska after making his official visit in October 2010. He attended the Huskers' game against Missouri and saw Pelini's defense sack Blaine Gabbert six times in a 31-17 win. Santos wanted to be a part of it.
A lack of depth at linebacker last year had Santos and the coaches thinking that he might step in and play immediately.
Looking back, Santos is glad he didn't, even though he found it difficult to not be able to play in games.
"It's an eye-opener, and it'll humble you real quick, realizing this is a whole 'nother level of play," Santos said. "Watching the first couple games and some of the tough losses, you think maybe if I had played I could have helped out. But that's not up to me; that's up to the coaches. I think everything worked out well in the end."