Spencer made his season debut on Sunday night and played 22 snaps, getting three tackles and one quarterback hurry in the 38-17 victory over the Saints.
Spencer's return to the field follows microfracture surgery on his knee. Few players return from such a surgery in the NFL, especially a pass-rusher such as Spencer.
"It feels good," he said. "It's what I've been waiting for, I've been working toward this for the last year or so. It's all the hard work paying off and now I got to start working hard on being a football player again."
Given the Cowboys' lack of pass rush from its defensive front, adding a player like Spencer can only help. He was a 2007 first-round pick, drafted to play outside linebacker in a 3-4 but when the Cowboys converted to a 4-3 two years ago, he was asked to move to defensive end.
But knee troubles slowed his progress in the last year and after playing in a Week 3 game at Kansas City, he was shut down.
Spencer didn't want the microfractue surgery because he was entering his free-agent year but he had no choice. The Cowboys gambled on him and signed him to a one-year deal with the hope he would add something to the defense.
He returned to the field on Sunday, played defensive end and took on right tackle Zach Strief on the first snap, one-on-one.
"Every game you have some kind of nerves but you still go out there and play," Spencer said. "I wasn't afraid, I knew my knee was going to hold up and I knew the things I've been doing have been working. I feel confident in how the surgery went and how it feels. I don't feel worried about that."