This season, Anthony Spencer has been cast as the most senior member of the Cowboys’ defensive line. It’s a role he’s well-suited for after unwittingly assuming the identity of his hoary character. He has a soft voice and long beard marked with gray flecks. He also recently spent approximately five months virtually immobilized, unable to move around without the aid of crutches.

“I laid down for about 16, 17 hours every day,” Spencer said.

Such is life for a 30-year-old NFL defensive end recovering from microfracture surgery in his left knee. The procedure, performed in October after Spencer played only one game last season, has usually spelled the end of athletes’ careers. Former Denver running back Terrell Davis and NBA star Tracy McGrady were never the same after undergoing the same type of operation.

It’s also far from certain whether Spencer will ever regain the form he showed in 2012, when he collected a career-high 11 sacks and was invited to his first Pro Bowl.

As of now, it’s not even clear whether he will be back on the field by Week 1. Spencer is not willing to announce a definitive date for his return, saying it’s merely a “possibility” he will make his debut at practice during the late stages of training camp. The reality is that Spencer could be placed on the physically unable to perform list before the Cowboys play their first game.

“We’re eyes wide open on this,” said Stephen Jones, the club’s executive vice president. “I won’t be totally surprised if he starts the season on PUP. Anthony thinks he might be back. I hope he does. We came into this knowing that he could be a PUP guy.”

That much was evident when the Cowboys finalized a contract with Spencer in April. The one-year deal, which could net Spencer a maximum of $3.5 million, is laced with incentives and includes a stipulation that would reduce his base salary to $423,000 if he lands on the PUP or injured reserve lists this season.

It’s a shockingly low amount for a player pegged with the franchise tag each of the previous two years, when Spencer received a grand total of $19.4 million. But his financial situation represents how much his lot in the NFL universe has changed in less than a year.

Once seen as an indispensible player, Spencer is now viewed as a spare part with a cloudy future. If he comes back and performs well, it’s a bonus. If not, the Cowboys’ defense won’t go bankrupt.

“I don’t know if you can count on any injured player to come back,” head coach Jason Garrett said bluntly. “You’ve got to make sure you have safety nets and reinforcements.”

Rebuilding the infrastructure of the defensive line was the Cowboys’ major project of the off-season. They bid farewell to seven-time Pro Bowler DeMarcus Ware and the team’s 2013 sacks leader, defensive tackle Jason Hatcher. Over time, they added nine players via the draft and free agency to bolster a flagging pass rush generated by aging veterans and NFL castoffs last season.

As this transformation unfolded, Spencer explored other opportunities. An unrestricted free agent, he visited the New York Giants and Washington in March but was ambivalent about joining either of the NFC East rivals. After all, he had established a life in Dallas.

“My family is here,” Spencer said. “My wife’s family is from here. We are building a house. I just had a baby. I really didn’t want to go anywhere else because of the fact my family is here and I am comfortable here. But it was a possibility. I didn’t want it to happen. But it could have happened. I was serious. If they had given me a contract I probably would have taken it. It was a business decision.”