PITTSBURGH -- Desperately in need of a win over the San Diego Chargers to improve their playoff chances, the Pittsburgh Steelers hoped Ben Roethlisberger's return would be the perfect spark.
Instead, the absence of cornerback Ike Taylor and linebacker LaMarr Woodley proved to be too much to overcome.
Roethlisberger and the Steelers' offense struggled while Philip Rivers and the San Diego receiving corps picked on backup corners Cortez Allen and Curtis Brown in a 34-24 win over Pittsburgh at Heinz Field.
"An unfortunate, poor performance by us, and by that I mean all of us," Steelers coach Mike Tomlin said. "We coached poorly today, we played poorly today. It's a shame given the opportunity that was in front of us, but it is what it is."
Rivers was 21 of 41 for 200 yards and three touchdowns, far from spectacular but more than efficient enough against a Steelers secondary missing its top shutdown corner due to a fractured ankle.
Allen, a second-year pro, got his first career start, but it was Brown whom the Chargers victimized the most. Brown was caught out of position on a 39-yard touchdown to Danario Alexander that helped give the Chargers a 13-3 halftime lead, and San Diego converted multiple third downs to receivers covered by Brown. Brown was eventually replaced by recently signed corner Josh Victorian.
"We wanted to give Josh an opportunity," Tomlin said. "They were attacking Curtis some, particularly on third downs. He wasn't being successful enough."
San Diego wide receiver Michael Spurlock said the Chargers were counting on Pittsburgh to be aggressive.
"If you know Pittsburgh, they are always trying to bring heat," Spurlock said. "They rely on their front seven so we figured that we could exploit their corners and our receivers are as good as theirs so we were able to make plays."
Even without three starters on the offensive line, San Diego gave Rivers enough protection. Woodley, second on the team in sacks, missed the game with a sprained ankle. Backup Jason Worilds couldn't team with fellow outside linebacker James Harrison to put much pressure on the Chargers, as the Steelers sacked Rivers just one time.
"We gave the two tackles game balls," Chargers coach Norv Turner said. "Kevin (Haslam) and Reggie (Wells) haven't been here a real long time. I think we did things to shut Pittsburgh down and they may not have played as well as some other teams we've played."
Emboldened by their first half success, the Chargers landed a heavy blow on the Steelers defense to start the third quarter. San Diego marched 78 yards over 18 plays and 9:32 before Rivers tossed a 3-yard touchdown to Malcom Floyd to give San Diego a 20-3 lead.
"That was ugly," Steelers linebacker Larry Foot said. "That's unchartered waters, right there, especially at home."
Turner said that the drive might have been San Diego's best of the season.
"The thing I liked about it is that we had a lot of people involved," Turner said. "Eighteen-play drives are hard in any league, but they're extremely hard in this league, particularly against this defense."
After a penalty on the ensuing kickoff return pushed the Steelers deep in their own territory, Roethlisberger tried a short screen pass to Antonio Brown on first down. The ball bounced off of tight end David Paulson, who was blocking on the play, and Quentin Jammer recovered it for the Chargers. The officiating crew reviewed the play to see if it was a forward pass, but it was ruled a fumble and the touchdown -- and San Diego's 27-3 lead -- stood.
Pittsburgh got a late touchdown on a 40-yard pass from Roethlisberger to Mike Wallace, but the Steelers couldn't muster much more of a comeback. Roethlisberger was picked off early in the fourth quarter, and Rivers tossed a 15-yard touchdown to Alexander to make it 34-10 and put the game out of reach despite the Steelers adding two late touchdowns. Roethlisberger finished 22 of 42 for 285 yards with three touchdowns and an interception.
Pittsburgh fell to 7-6, but stayed tied for the sixth and final playoff spot thanks to Dallas' 20-19 win over Cincinnati. That makes the Bengals' trip to Pittsburgh in two weeks essentially a playoff game.
Even with the win, San Diego is all but out of the playoff hunt at 5-8.
Notes: Rivers didn't throw an interception, marking the first time this season that he went back-to-back games without throwing a pick. ... Recently signed wide receiver Plaxico Burress made his first catch in a Steelers uniform in eight years. Burress, signed on Nov. 20, hadn't played since the end of the 2011 season when he was with the New York Jets. The 35-year-old Burress was active for the last two games but didn't record a stat. He was originally drafted by Pittsburgh as the No. 8 overall pick in the 2000 NFL draft. ... San Diego DE Vaughn Martin left early in the first with a groin injury and did not return. ... Steelers left guard Willie Colon injured his left knee and did not return. Center Maurkice Pouncey moved over to left guard and Doug Legursky came into the game to play center.