It's a minor miracle that he's even playing again, but Spencer's goal now is earning back his job.
"I'm taking it day by day. I ain't rushing nothing," said Spencer. "I'm excited to show these coaches what I can do."
Ephraim Salaam has started at left tackle in all 30 games since Spencer's injury. The Texans used their first-round pick this year on tackle Duane Brown and Coach Gary Kubiak said Brown is the frontrunner to take over position this season.
Spencer showed the same potential when the Texans drafted him in the third round in 2006. He was the Texans' starting left tackle for the first two games of 2006, but was injured in the third quarter of his second game, Houston's 43-24 loss to Indianapolis on Sept. 17.
When it happened, Spencer thought he had only sprained his knee. But team physician Dr. Walter Lowe gave him the ominous diagnosis after an X-ray -- spiral fracture of the tibia with torn cartilage under his kneecap.
"That's when it set in," said Spencer, a college standout at Pittsburgh. "I had worked so hard, coming from the north and coming down and working in this heat and fighting for a starting job. It was tough. I had to face a lot of adversity and I had some more to deal with."
Spencer had surgery the day after sustaining the injury. His leg was immobilized for two weeks and months of painstaking rehabilitation followed. Spencer relied on teammates to keep his spirits up and drew daily motivation from his daughters, Nhyairah and Vizzsun, who are now 5 and 1 1/2.
"I've got a family to take care of and I've got to support them," Spencer said. "If I'm not coming to work and working hard, then I'm not providing for the family."
He had another surgery last June and doctors discovered that the cartilage was growing back and that the injury was healing properly.
"It was a very severe injury on a very large man," said Texans head athletic trainer Kevin Bastin. "He's been very disciplined in his work and his rehab process and the small steps we've been taking with him really paid off."
Once he was able to run again, Spencer had to overcome the fear of re-injuring it.
"For a while, I was kind of half-stepping," he said. "What can I do? How fast can I come back? Once you get over that hump, that was probably the biggest thing, just trusting it." Spencer joined some teammates for running and conditioning drills about a month ago. He was so eager to test his leg, he had to hold himself back.
"I was flying up and down the field," he said.
The time out gave Spencer a new, humble perspective. He was a star in college, an All Big East selection in his junior and senior seasons. In the pros, he's just another player fighting to stay on a roster.
"It's a business and everybody is replaceable," Spencer said. "If you don't prepare yourself as being the best, or being elite, then you're replaceable. I have to approach that every day."
Spencer was wearing a knee brace during Friday's workout and Kubiak said he'll hold Spencer out of full-squad drills during the minicamp. Spencer will gladly follow Kubiak's orders as long as he's considered for his old job in the fall.
"This is huge, because I went from a starting role to not playing to playing behind guys right now," Spencer said. "I've got to work hard to get back in the starting lineup. I can get in my stance, I can explode. I'm looking forward to contributing."
If it doesn't work out at left tackle, Spencer said he'd be willing to play either guard spot. After two seasons impatiently watching from the sideline, he just wants to play again.
"It can hurt. You're used to doing something every day and you can't do it for a certain amount of time," Spencer said. "I've adjusted to it. I've taken a little detour, but I'm back on track."