MINNEAPOLIS — That clean, crisp Raiders team that showed up in the exhibition opener didn’t make the trip to Minneapolis for the second game.

Coach Jack Del Rio said he thought the 20-12 loss to the Minnesota Vikings on Saturday night bore some similarities to the Raiders’ 18-3 win over the St. Louis Rams eight days earlier.

Perhaps so, but not in key areas such as playing smart football.

The Raiders were flagged 13 times, including three false starts and two for not lining up correctly. One of the false starts came on the first offensive play when left guard Gabe Jackson got a head start.

“Clearly not the kind of clean performance that we’re looking for,” Del Rio said.

Del Rio tried to push some of the blame onto the officials, noting the discrepancy in penalties. The Vikings were flagged just once.

It’s apparently never too early to start ragging on the referees.

HELPED THEMSELVES

Running back Michael Dyer led the team with 45 yards on 12 carries. The undrafted rookie showed the burst and wiggle he has displayed in practice. He has a knack for making something out of nothing. For instance, on one play, the Vikings had him pinned for a loss, but he turned it into a gain.

Linebacker Ben Heeney led the Raiders in tackles for the second straight game. He had seven stops, including a half-sack and a forced fumble. His nose for the ball is so strong that he even pushed teammate Neiron Ball out of the way on one occasion to get in and contribute to a stop.

Wide receiver Amari Cooper showed the big-play ability he has with a nice burst to burn cornerback Terence Newman for a 40-yard completion, the biggest play of the game.

Defensive end Shelby Harris, who had a sack last week, nearly intercepted a screen pass and then two plays later recovered a fumble.

Defensive end Mario Edwards Jr. joined Heeney on that sack and also applied pressure a couple other times on the quarterback. BEARS WATCHING

Wide receiver Seth Roberts drew the ire of quarterback Derek Carr when he didn’t haul in a deep pass that went off his hands. He also bobbled a pitch on an end around, although he secured possession and gained 2 yards. He bounced back later with a nice crossing route that became a 39-yard catch and run.

Defensive end Benson Mayowa got the start on the right side with Justin Tuck not suiting up. He moved over to the left side after Khalil Mack left the game. Mayowa had three tackles and one hit on the quarterback but was often stalemated at the line while rushing. HURT THEMSELVES

Running back Trent Richardson had just 5 yards on five carries. He looks hesitant when he gets the ball and doesn’t have the speed to hit small creases or make something happen when the hole isn’t there.

Cornerback DJ Hayden had an awful night. He was burned for a touchdown, although it was a great throw from Vikings quarterback Teddy Bridgewater. An illegal-contact penalty negated a third-down stop, and he incredulously played well off receiver Charles Johnson on a fourth-down play. Hayden backed up to the first-down marker just before the snap, retreated more afterward, and Bridgewater hit Johnson for what the Vikings’ broadcast accurately called “an effortless first down.”

Offensive lineman Tony Bergstrom was whistled for a false start and a holding penalty. He also delivered a low shotgun snap on a third-and-goal play. Quarterback Christian Ponder did well to catch the snap, but it played a role in his having to scramble out to the right. His pass to the end zone to Kenbrell Thompkins was just out of bounds.