The fifth in a series looking at each of the Dallas Cowboys’ position groups:

Players: Flozell Adams (signed through 2013), Marc Colombo (signed through 2012), Doug Free (signed through 2010), Robert Brewster (signed through 2012), Pat McQuistan (restricted free agent)

What went right: Free’s development was extremely encouraging for a franchise that had endured a horrible stretch of offensive line draft busts.

Free, a fourth-round pick in 2007, was impressive enough filling in at right tackle for Marc Colombo (broken fibula/torn ankle ligaments) in the final seven games that there was some debate about whether the veteran should have reclaimed the starting job for the playoffs.

Free isn’t as physical as Colombo, who is considered the line’s leader, but the younger tackle has good athleticism and never gives up on plays. His downfield block on Felix Jones’ long touchdown run in the regular-season finale – Free sprinted diagonally across the field and shielded a defensive back to escort Jones into the end zone – was one of the rare times a tackle gets featured on the highlights.

Adams has his flaws, but he’s still an outstanding run blocker who would start at left tackle for most teams in the league. The Cowboys averaged 6.3 yards per run behind left tackle, which ranked third in the league.

What went wrong: Let’s start with the end. The Minnesota Vikings’ defensive ends made the Cowboys look awful in Dallas’ lopsided playoff loss. Colombo, who rushed back from injury for the playoffs, clearly wasn’t 100 percent as he got dominated by Ray Edwards.

Adams, 34, is showing signs of age. He’s always had a lot of false starts (six this season), but he was penalized several other times because he had to make up for being beaten by quicker foes. He allowed eight sacks, which was tied for the 14th most in the league. Colombo, 31, also wasn’t as effective as he was the previous season before he was injured.

Third-round pick Robert Brewster, who could end up moving inside to guard, basically lost a year of development. He has yet to put on shoulder pads as a pro after missing the entire season due to a torn pectoral suffered while lifting weights during the summer.

What’s next: Free’s development prevented tackle from being a desperate draft need, but it’s still a top priority. The Cowboys must prepare for a future without Adams and Colombo.

It will be interesting to see if Free is given a legitimate chance to earn a starting job, either at left or right tackle. His performance as Colombo’s replacement merited that kind of opportunity.

Adams is likely to return despite his big contract and declining talent. He is still valued around Valley Ranch, although this could be the longtime left tackle’s final season with the Cowboys.