But potentially even more concerning than the team's 28-26 loss were the early departures of two key offensive starters.
Ben Roethlisberger exited late in the second quarter with an elbow injury to his throwing arm, and running back James Conner left in the fourth quarter with a knee injury. Both were labeled questionable to return, but neither came back. After the game, coach Mike Tomlin said both players were being evaluated, along with a handful of other injured players including Sean Davis (shoulder), Vince Williams (hamstring) and Anthony Chickillo (plantar fasciitis).
"We lost a number of guys in this game, but that wasn't the reason why we didn't win this game," Tomlin said. "We were fully capable with the guys that were on the field. We didn't make enough plays, to be quite honest with you. We didn't play clean enough, particularly in some moments. We've got to get better. We accept responsibility."
Roethlisberger grabbed his throwing elbow after attempting a pass on the Steelers' final drive of the half.
In Roethlisberger's absence, second-year quarterback Mason Rudolph nearly led the Steelers to a fourth-quarter comeback in his first career appearance, completing 12 of 19 attempts for 112 yards, two touchdowns and an interception.
Rudolph, a 2018 third-round pick, started the second half, fist-bumping Roethlisberger before he ran out on the field, and the two talked in between drives throughout the rest of the game.
"We didn't change the offense for him," Tomlin said. "Mason's capable. He's been a part of this thing. He's the backup quarterback. We're capable of functioning in a very normal manner when he's in there and we did."
Under the young QB's direction, the Steelers scored a field goal and two second-half touchdowns -- both coming on passes from Rudolph to tight end Vance McDonald.
Rudolph's first drive was brief as his second passing attempt was picked off when the ball bounced off Donte Moncrief's hands on third-and-long. Safety Bradley McDougald made the diving grab to intercept it.
Rudolph rebounded, though, on the next drive as he hit receiver JuJu Smith-Schuster on a 45-yard flea-flicker. The drive eventually stalled in the red zone for a short field goal.
In the fourth quarter Rudolph threw two touchdown passes, including the first of his career, and pulled the Steelers within two points with five minutes remaining. The second touchdown came after rookie Devin Bush picked up a fumble on a botched snap deep in Seattle's territory and returned it to the 3-yard line. Rudolph hit McDonald over the middle for a 3-yard touchdown on the next play for the tight end's first multitouchdown game of his career.
"He's going to throw the ball and make his reads," McDonald said. "I think he is very deliberate about that, and that is something we can look forward to on offense. I think he's come a long way since last year. If he's our guy, then he's our guy, and we have to move forward with him."
The offense showed a renewed energy under Rudolph's direction, converting two of five third downs in the second half after managing just one of six in the first.
"Lot of confidence," right guard David DeCastro said of Rudolph. "He came in, obviously, knew the plays, mixing up snap counts -- not much drop-off, if any. I was really impressed to see that."
Roethlisberger, who was 1-of-4 on passes thrown more than 5 yards downfield, briefly went into the locker room, but was on the sideline for the last two minutes of the first half and for all the second half.
In the event Roethlisberger can't go next week, Rudolph will be ready. While lamenting the starting quarterback's injury, the Steelers also voiced their belief in Rudolph in the locker room afterward, and Rudolph expressed as much from the postgame podium.
"I'm completely confident," Rudolph said. "I've always been confident in myself, in being the leader of the team and winning games. That's what it ultimately comes down to. If that's the case, then I'll be ready to roll."