After losing five of their previous six games, the Steelers produced a season-high four turnovers and turned two of them into touchdowns. That proved to be the difference in a 24-10 defeat of Cleveland that pulled the door closed on a season draped in mediocrity and disappointment.

A Steelers team with a playoff-caliber roster and February hopes fell into the NFL sea level of 8-8. It’s an acceptable record in many pro-football ports, but not Pittsburgh. Worse, it followed a 6-3 start that was already pocked by losses to two bottom-feeder teams, Oakland and Tennessee.

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Such a losing trend continued through the 2-5 second half, pocked by losses to Cleveland and San Diego. Indeed, 60 starts were lost to injuries to players who opened the season as first-teamers. Yet this franchise has overcome a litany of injuries in previous seasons.

On Sunday, the Steelers avoided getting swept this season by Cleveland for the first time since a young Bernie Kosar in 1988. The triumph was a microcosm of their season: backups thrust into roles, more injuries, steady defense and inconsistent offense.

Offense: D

The offense that was forecast to carry the Steelers couldn’t even lift its own weight in the end. The home team manufactured one drive more than 50 yards and just two more than 27 yards as it failed to conjure more than 24 points for the ninth consecutive week. An offense so proficient on third down early in the season, ranking among the NFL leaders, transformed into a gang that failed to convert three third-and-shorts Sunday in a continuing, alarming trend. Ben Roethlisberger and the offense never did settle upon an identity, and their top rusher -- Jonathan Dwyer -- opened the year as their No. 4 halfback and finished it with the fewest yards to lead a Steelers team since 1991. They played Sunday without an injured tight end Heath Miller and wide receiver Mike Wallace, who may well find a richer contract elsewhere, so they showed a need for more skill. That battered offensive line used its eighth different combination of regulars in a 16-game schedule, too. No wonder they had identity problems: The offense used 24 different starters all season. Previous game's grade: D

Defense: A

The Steelers’ defense returned to its No. 1 NFL ranking with a hint of panache: They allowed just one touchdown in their final two regular-season games, and only once in the final 11 games allowed more than 24 points in regulation. True, Cleveland, due to injuries, was starting its No. 3 quarterback and its backup tailback, and in the course of the game lost its second-leading wide receiver, too. Still and all, the Pittsburgh unit coordinated by Dick LeBeau resembled its old, stingy self except in one regard: Its 10 interceptions on the season marked a franchise low for a 14- or 16-game schedule. Amazingly, seven of its total 20 takeaways for the year came in those final two regular-season games. Second-year cornerback Cortez Allen had a hand in five of them, perhaps providing a glimpse into the future. Previous game’s grade: B-

Special teams: B+

The Steelers held nemesis Josh Cribbs in check, though the one time he did break loose it was nullified by a Cleveland penalty. Rookie punter Drew Butler kicked away from Cribbs five times. He was the recipient of some decent bounces in averaging 41.8 yards per kick -- his fifth-lowest this season -- but, impressively compiled a 40.7 net. Previous game’s grade: C

Coaching: C

A reshuffled offensive line, a passing attack minus Miller the Pro Bowl tight end and Wallace the 2011 Pro Bowl receiver due to injury, a defense that lost its captain (Brett Keisel) and its top remaining cornerback (Keenan Lewis), and a team psyche that was playoff-less and potentially rudder-less. Mike Tomlin and staff were able to rally the Steelers after an early Browns push and pull out only the second victory in the final seven weeks of the season. It isn’t deserving of a gold star, but they’ll get to keep their lunch and recess privileges. Previous game’s grade: D

Follow Steelers reporter Chuck Finder on Twitter @CBSSteelers and @cfinder.