Minnesota Vikings quarterback Case Keenum (7) gets off a pass while being hit by Pittsburgh Steelers defensive end Tyson Alualu, rear, and outside linebacker Arthur Moats (55) during the second half of an NFL football game in Pittsburgh, Sunday, Sept. 17, 2017. (AP Photo/Don Wright) PITTSBURGH (AP) — Pittsburgh Steelers linebacker Bud Dupree was so locked in to his assignment, that he had no clue the Minnesota Vikings started Case Keenum for injured quarterback Sam Bradford until the second series of Pittsburgh’s 26-9 victory on Sunday, when Dupree found himself chasing the sub.“Then I got back there (in the backfield), I knew (Bradford) was way taller and I was like, ‘that ain’t even him,’” Dupree said.Dupree spent most of the rest of the afternoon getting a close-up look at Keenum, spearheading another solid defensive performance by the Steelers. Pittsburgh (2-0) held the Vikings to 237 total yards, sacked Keenum twice and kept Minnesota rookie running back Dalvin Cook under wraps.For a team that spent most of the offseason talking about its high-powered offense, the guys on the other side of the ball are more than holding their own until the “Killer Bs” gets it together.“We know the offense is going to score points,” Dupree said.Maybe, but not yet. The Steelers have only four offensive touchdowns through two games, forcing the defense to be something more than adequate. So far, it hasn’t been an issue, though Pittsburgh is well aware sterner tests await after facing Cleveland rookie DeShone Kizer and Keenum — a journeyman who got the nod when Sam Bradford’s swollen left knee prevented him from playing — in the first two weeks.“You see leaps and bounds (of improvement),” defensive end Cam Heyward said. “We’re better in some instances, whether it’s our technique and execution. But we’ve got to get better. It’s just two games. I’m not going to jump head over heels because it’s two games.”Still, Dupree borrowed one of head coach Mike Tomlin’s favorite “Tomlinisms” when he offered “we have the arrow pointing up” when asked about the strides the defense is making. Pittsburgh has allowed just 474 net yards through two games, an impressive start for a group that finished a pedestrian 12th in the league in 2016.“We’re going to be a great team all the way around,” Dupree said. “Don’t want to be an offensive team or a defense team. … We just want to keep it rolling.”Some other takeaways as the Steelers improved to 10-1 in home openers under Tomlin.SAM’S STATUS: Vikings coach Mike Zimmer stressed Bradford is going to be “OK.” Other than that, everything else about Bradford’s status is a mystery. Asked to give a timetable on how long Bradford might be sidelined, Zimmer said he wasn’t going to offer any sort of specifics.“Maybe next week, maybe six weeks from now,” Zimmer said. “(Bradford) is going to be OK. It’s non-surgical so he is going to be fine.”FLAG DAY: Tomlin promised the Steelers would improve after drawing 13 penalties in the opener against Cleveland. He was right, but only by a little. The Steelers were flagged 10 times for 72 yards. The Vikings weren’t any better, earning 11 penalties for 131 yards, including a pair of pass interference calls that directly set up Pittsburgh touchdowns.“I’d like us to play cleaner,” Tomlin said. “I respect the flags thrown.”ROLLING, ROLLING, ROLLING: Pittsburgh wide receivers Martavis Bryant and JuJu Smith-Schuster both threw imaginary dice while celebrating their first touchdowns of the season. Bryant said it was something the receivers came up with during the week following a brainstorming session. They plan on mixing it up week to week. The Steelers drew a delay of game penalty after Bryant’s score, a flag Tomlin took the blame, saying “it was more of a procedural thing on my part.”OLD FRIENDS: Steelers wide receiver Antonio Brown and Vikings cornerback Xavier Rhodes grew up in Miami, going to the same high school. They were two years apart at Miami-Norland and held an impromptu reunion at Heinz Field. Brown ultimately got the upper hand, finishing with five receptions for 62 yards.“Our battle was good,” Rhodes said. “We had fun but at the end of the day we still wanted to win.”INJURY UPDATE: Pittsburgh rookie LB T.J. Watt left in the first half with a groin issue but said he considers it “something minor.” Steelers TE Jesse James is dealing with a left ankle issue. Left tackle Alejandro Villanueva missed part of the second half due to “heat related issues” on a day the temperature at Heinz Field hovered in the mid-80s.___For more NFL coverage: http://www.pro32.ap.org and http://www.twitter.com/AP_NFL .