AP photo Pittsburgh Steelers quarterback Aaron Rodgers (8) gestures to the sidelines after being sacked during the second half against the Seattle Seahawks on Sunday in Pittsburgh.

PITTSBURGH — Mike Tomlin has long believed NFL teams make their biggest improvements from Week 1 to Week 2.

This time around, the league’s longest-tenured coach might want to hope he’s wrong after watching the Pittsburgh Steelers pratfall their way through a 31-17 loss to Seattle on Sunday.

Aaron Rodgers threw a pair of interceptions. The defense that began the season full of swagger was pushed around. And rookie running back/kick returner Kaleb Johnson took a play off at the worst time, gifting the Seahawks a touchdown on a day Seattle didn’t need much help.

Seven days after a stirring comeback over the New York Jets, the good vibes vanished quickly.

“Really disappointed,” Tomlin said. “We’ll get better. We have to.”

In a lot of areas. Rodgers took three sacks and was hit a half-dozen other times, though 41-year-old four-time MVP didn’t put the blame on a young offensive line that has done little to make his job easy through two weeks.

“Sometimes it was me, sometimes it’s somebody in front,” said Rodgers, who threw the 508th touchdown pass of his career in the second quarter to tie former teammate Brett Favre for fourth on the NFL’s career list. “We just got to own our mistakes and be very accountable to each other and take this kick in the chin the right way and be a professional about it.”

Johnson, a third-round pick out of Iowa who was expected to challenge Jaylen Warren for the starting job but instead has been relegated to kick-return duty, will spend the next week getting a crash course in resiliency.

The Steelers were trailing by three early in the fourth quarter when Johnson let a kickoff go through his hands. Rather than chase it, he walked off the field. Seattle’s George Holani fell on it for a touchdown that gave the Seahawks a 10-point led they never threatened to give away.

“If I wasn’t sure (of the rule), or I was sure, it doesn’t matter,” Johnson said. “I still got to go in there and execute the way it needs to be executed.”

Tomlin was careful not to put too much of the focus on Johnson, not on a day the defense gave up 395 yards. Not after the Steelers allowed 30 points in each of their first two games for the first time since 2002.

“I have a desire for us to be cleaner so you can’t point to singular plays as pivotal points in the game,” Tomlin said.

The Steelers, who were already without cornerback Joey Porter Jr. (hamstring) and rookie defensive lineman Derrick Harmon (knee), lost linebacker Alex Highsmith and defensive tackle Isaiahh Loudermilk with ankle injuries against Seattle.

“It’s funny because we scratch our head about the (early) bye week and we’re like ‘Damn, we might need the bye week pretty soon,” defensive tackle Cam Heyward said. “I worry less about how many people we’re going to have and more about us doing our job and being more sound in our assignments.”

The Steelers are still two games away from getting a break. Between now and then there’s plenty to clean up, or a season that began with promise might turn into something else.

“You can’t hang your head,” Rodgers said. “We expect greatness, but we also understand there’s going to be mistakes. They happen. We’re human. You must move on and get better.”