FRISCO — The Cowboys’ plan for their offensive line was based on hope.

Now the plan is in the trash.

Starting left tackle Tyron Smith is lost for the majority of the 2022 season with an avulsion fracture of his left knee. The part of the hamstring behind the knee is torn, and a person with knowledge of the situation said Smith will undergo surgery Friday. Cowboys owner and general manager Jerry Jones said Thursday night he hopes Smith returns before the playoffs. That’s late December or January.

The original plan for the 2022 season was to have Smith play 17 games. It was an ambitious but flawed plan. Smith hasn’t played a full season since Barack Obama was president. After starting a total of 52 games in four consecutive seasons, Smith entered the 2022 campaign participating in just 13 over the last two years.

He had neck surgery in 2020, costing him 14 games. But Smith returned to his elite form and started 11 games last season, missing time with an ankle injury and being on the COVID list.

Smith earned his eighth Pro Bowl selection in 2021. He even fought through an arm injury toward the end of the season, prompting him to wear braces on both arms this summer.

“Just very unfortunate. Heartbroken for him,” quarterback Dak Prescott said. “A guy who has battled his whole career, battled little injuries here and there, just for something like that to happen. It’s just unfortunate. It’s just what this game brings to you, things you can’t control.”

The worries about Smith’s health were always a concern for the Cowboys. It made sense when they drafted offensive lineman Tyler Smith in the first round.

But they should have also signed a veteran tackle, in case something happened to Tyron Smith.

It’s easy to say this now.

However, when the Cowboys released La’el Collins, the starting right tackle last season, it meant the franchise was going to depend on unproven talent to provide depth.

And now the replacements for Tyron Smith don’t appear ready for the big stage.

The leading candidate is right tackle Terence Steele. He started six games at left tackle for an injured Tyron Smith.

Tyler Smith could also just move to left tackle and start the process of taking over now.

Jerry Jones was noncommittal about Tyler Smith making that move.

“I want to see how this works out,” Jones said. “We obviously, when we drafted him, we thought of him as a left tackle and anticipated that’s why we made him the No. 1 pick. Right now, we may have a different way we want to go with it. Make no mistake about it, though. It’s going to mean a lot more snaps than maybe he or we had planned for Tyler.”

Other candidates are Josh Ball, Aviante Collins and Matt Waletzko. Of these three, only Collins has played in a regular-season game. Collins, a TCU product, has played in five games since Minnesota signed him as an undrafted free agent in 2017. Ball is the swing tackle for the moment. If someone can’t establish themselves at left tackle, a trade or signing someone off the street is the next option.

The problem is the opportunity to build continuity along the offensive line is compromised with just one preseason game remaining. If the Cowboys sign a veteran, that chemistry is going to be difficult to achieve. Also with Tyler Smith nursing a sore ankle, you can’t get a good look at him at left tackle because he’s going to miss Friday’s preseason finale.

In the big picture, Tyron Smith’s injury might accelerate plans to release him next spring and force the Cowboys to look at their offensive line plan again.

There is no more guaranteed money on his contract, and he’s signed through next year with a base salary of $13.6 million. If the Cowboys make him a post-June 1 cut, there’s roughly $8 million in dead money and $9.5 million in savings.

When Tyron Smith was drafted ninth overall in 2011, it meant the beginning of the rebuilding of the offensive line. A unit that was neglected for a time became a strength. Tyron Smith played the position at an All-Pro level and should get Hall of Fame consideration.

He turns 32 on Dec. 12.

His career is not over. His season might not be over.

But his place in the Cowboys’ long-term plan is over.

Twitter: @calvinwatkins