Steelers coach Mike Tomlin thought the injury was a non-issue, and perhaps it was given the way the former Pro Bowl quarterback played. One thing is certain: The Chiefs sure wish it had been a bigger problem.
Roethlisberger threw a short touchdown pass to Weslye Saunders in the first half, and the Steelers took advantage of four turnovers by Chiefs quarterback Tyler Palko in a 13-9 victory that allowed them to keep pace with Baltimore atop the loaded AFC North.
''They're a good football team, good defense,'' Roethlisberger said. ''It's tough because it's a mixed feeling type of thing: You're happy to get the win, but you're disappointed the way the offense played. I think that's what team's all about. The defense stepped up huge today.''
Roethlisberger finished 21 of 31 for 193 yards and an interception for the Steelers (8-3), whose defense lost All-Pro safety Troy Polamalu to a head injury in the first quarter yet still managed to keep the bumbling Chiefs (4-7) from scoring a touchdown.
Kansas City has reached the end zone only once since beating San Diego on Oct. 31.
The Chiefs nearly did on their final possession, marching across midfield to the 37. That's when Palko dropped back and looked for Dwayne Bowe, but his throw was high and behind him, and Keenan Lewis hauled in the interception with 29 seconds left to seal the win.
''I just read the quarterback. I knew I had help underneath, so I could stay back and protect deep,'' Lewis said. ''When the ball came out of the quarterback's hand, I saw that Bowe had already made his move. That's when I knew I could make a play.''
Palko fared little better than he did last week against New England, when he tossed three picks in his first NFL start. He finished 18 of 28 for 167 yards in what was likely his last chance. The Chiefs claimed former Broncos quarterback Kyle Orton off waivers Wednesday with the intention of having him compete with Palko for the starting job.
Orton didn't arrive in town until Friday, though, and he was inactive Sunday night after participating in only one practice.
''He'll have a much better chance this week to compete,'' Chiefs coach Todd Haley said, ''and like I said, Tyler is the starter, but whatever position we say, if someone gives us a better chance to win, that's the guideline we generally follow.''
Kansas City led 3-0 in the second quarter when Palko's first interception, which Taylor returned to the Chiefs 8, resulted in a 21-yard field goal by the Steelers' Shaun Suisham.
The second pick was returned by Mundy, who had taken over at safety for Polamalu, to the Kansas City 24.
The defense appeared to hold Pittsburgh when Tamba Hali sacked Roethlisberger on third-and-7, but safety Jon McGraw was called for defensive holding to give the Steelers a first down. Three plays later, Roethlisberger found Saunders in the back of the end zone.
''He was kind of one of the last options,'' Roethlisberger said. ''I saw Wes coming in the back of the end zone, he's kind of a big target, so I just kind of threw it up to him.''
Ryan Succop added a 49-yard field goal later in the second quarter for Kansas City, his second of the game, but Suisham answered with his own 49-yarder on the final play of the first half.
Succop added a 40-yard field goal with 6:11 left in the fourth quarter.
Polamalu left the game in the first quarter when he tackled 290-pound Chiefs offensive tackle Steve Maneri, who had caught a pass in the flat after lining up in the backfield. The reigning Defensive Player of the Year's head hit Maneri's knee and he crumpled to the turf, where he lay while trainers came out to check on him.
Polamalu was a bit wobbly when he stood up and Tomlin said after the game that he was experiencing ''concussion-like symptoms.''
Roethlisberger showed little evidence of the broken thumb that caused him to be somewhat limited in practice, hitting 10 different receivers. He got some help from Rashard Mendenhall, who ran for 57 yards, and a defense that kept giving the Pittsburgh offense prime field position.
The Steelers squandered a promising opportunity in the first quarter, driving inside the Chiefs 10-yard line. But backup running back Mewelde Moore had the ball poked out by Chiefs linebacker Tamba Hali and it was recovered by Javier Arenas in the end zone for a touchback.
Kansas City gave the ball right back when Palko fumbled the snap moments later.
Pittsburgh also had a decent drive end midway through the scoreless third when Roethlisberger underthrew Antonio Brown down the sideline. Kansas City safety Travis Daniels swooped in to make the interception, but the Chiefs' bumbling offense couldn't capitalize.
That wound up being the story of the game.
''We're excited about winning - and winning on the road - and making the necessary plays,'' Tomlin said. ''We produced turnovers tonight, and that was big for us.''
Notes: Kansas native Martina McBride sang the national anthem. Modern Family's Eric Stonestreet, who attended Kansas State, threw the ceremonial first pass. ... Steelers C Maurkice Pouncey left in the first half with a stomach virus. ... The Chiefs finished with 252 yards of total offense.