Top Stories Grace expects Greinke trade to have emotional impact — If tight end Troy Niklas can just stay healthy this season, we may finally see the immense all-around talent the 6-foot-6, 270-pound Notre Dame product possesses.— Fourth-round pick Evan Boehm has struggled to pick up the nuances of the center position in training camp practices, but he looked pretty good on Friday, including an impressive pancake block on one running play. How long before the 6-3, 310-pound center of the future replaces A.Q. Shipley and becomes the center of now? Shipley got pushed off the line by bull rushes a couple times against the Raiders. That is the main concern.— Backup QB Drew Stanton and third-string quarterback Matt Barkley were not sharp in relief of Palmer. That’s not a concern for Stanton, who knows the system well, but it’s a concern for Barkley, who is trying to win the third-string job, but has not impressed Arians.“Good and bad and ugly,” Arians said of Barkley, noting that he failed to send the motion on three plays. “He can make every throw. It’s just all those little things that he’s got to clean up.”— Special teams coordinator Amos Jones is going to hold a long film session next week. His units have a lot of work to do. On that note, can the Cardinals afford J.J. Nelson on punt returns? He’s fast but ball security is often an issue, as it was when he muffed a punt that led to Oakland’s first TD. “Not up to my standards,” Humphries said of his game. “I felt like I was too hyped to start the game — too excited, too amped up and oversetting. Just dumb stuff that I wouldn’t normally do. I was being over-aggressive and it wasn’t working for me so I realized I had to calm down.”Arians was positive in his assessment of both Humphries and Williams and that makes sense from a players’ coach. Arians needs to build up both players’ confidence and he recognizes that this is just one preseason game so there is no sense dwelling on the struggles, even if they were plain for all to see. He needs both players to perform this season so this will no doubt become a teaching moment.— The Cardinals’ running back depth is ridiculous. David Johnson showed off the moves that have made him a fantasy darling this season when he juked cornerback David Amerson in the second level and ran for 23 yards. A healthy Andre Ellington racked up 41 yards on three carries in the first half, and fourth back Kerwyn Williams had five carries for 26 yards. With Chris Johnson cemented at No. 2, the Cardinals are going to have some tough decisions to make with Stepfan Taylor and big Elijhaa Penny also warranting consideration. 41 Comments Share Follow Craig Morgan on Twitter – / 12 Derrick Hall satisfied with D-backs’ buying and selling — Rookie cornerback Brandon Williams looked fine against reserve receivers. He even came up with a fumble recovery and drew an offensive pass interference penalty.The problem for the Cardinals is that they are talking about starting Williams, the guy with one year of cornerback play on his resume. When Williams was matched up against Oakland’s top receivers, Michael Crabtree, Amari Cooper and Andre Holmes, he didn’t fare as well.Oakland quarterback Derek Carr looked his way on the Raiders’ first offensive play and completed a 16-yard strike out to Crabtree with Williams giving Crabtree a huge cushion.Cooper beat Williams badly with a double move to the sideline and caught the pass, but one foot was out of bounds. If the throw had been better, it would have been a big gain; possibly a touchdown.Cooper beat Williams again on the Raiders’ second offensive series, and Holmes beat him in the end zone for Oakland’s second touchdown on nicely thrown ball.“You knew they’d go after him,” coach Bruce Arians said. “Amari Cooper is a heck of a player and (Williams) handled his own… He’ll learn to play those balls better.” GLENDALE, Ariz. — Before continuing with this story, you should apply the usual preseason qualifiers to everything you are about to read. Preseason games are meaningless, preseason games are always littered with mistakes and preseason games should never be interpreted as signs of what’s to come in the regular season.With that in mind, here are some observations from the Cardinals’ 31-10 loss to the Oakland Raiders on Friday at University of Phoenix Stadium. Former Cardinals kicker Phil Dawson retires We know Arians believes in competition, and cornerback Justin Bethel needs some time to round into game shape after offseason foot surgery landed him on the PUP list, but his $9 million in guaranteed money and his greater experience make it hard for us to believe the Cardinals are ready to go to war with a player as green as Williams.This sounds suspiciously like the motivational bluster you always hear from coaches in training camp, but Williams seems to be taking it all in stride.“Ups and downs — what I expected because I just started playing the position,” Williams said of his performance. “I had some good plays and some bad plays.”— Arians liked right tackle D.J. Humphries’ performance in the run game, but Humphries didn’t fare well when he didn’t have help in the passing game. Maybe that’s a reality the Cardinals will have to adjust to this season.Oakland’s elite defensive end, Khalil Mack, twice beat Humphries badly to the inside with body fakes, and Humphries needed help from running back David Johnson and guard Evan Mathis to avoid allowing pressure. On Mack’s second pressure, QB Carson Palmer was forced to throw the ball away and the Cards settled for a field goal.