Doug Free, a key member of the Dallas Cowboys' stellar offensive line, is retiring from the NFL after 10 seasons. 

ESPN.com's Todd Archer reported Saturday that Free informed the team of his intention to retire at the age of 33. Clarence Hill Jr. of the Fort Worth Star-Telegram confirmed the move.    

Free spent his entire career with the Cowboys, who made him a fourth-round pick out of Northern Illinois in 2007. 

After playing in just one game over his first two seasons, Free was an iron man for the Cowboys. He appeared in 80 straight regular-season games from 2009 to 2013, including starting 64 consecutive contests. 

Free was the Cowboys' starting left tackle from 2010 to 2011 before swapping positions with Tyron Smith, who was a first-round pick in 2011 and started at right tackle as a rookie.

The Cowboys have lined up Free at right tackle for each of the past five seasons. Foot and ankle injuries in 2014 caused him to miss five regular-season contests and the Cowboys' two playoff games against the Detroit Lions and Green Bay Packers.

Along with Smith, Zack Martin and Ronald Leary, Free has been part of one of the NFL's most dominant offensive lines for the past three seasons. 

Sam Monson of Pro Football Focus did note Free was the weakest link on Dallas' O-line last season, "struggling with his run blocking" and allowing eight sacks.

Archer highlighted 2015 third-round draft pick Chaz Green as an option to replace the veteran, though he's only appeared in four games over the past two seasons. 

Emmett Cleary is another option for Cowboys head coach Jason Garrett. He appeared in 13 games in 2016. 

Even though Free was no longer at the top of his game, his veteran presence and his understanding of the Cowboys' system made him a good fit alongside a dominant group. It will still be a terrific unit in 2017, but the front office will have to figure out the depth at right tackle in free agency or in April's draft.