Video (04:54) : Vikings running back Adrian Peterson said he liked how he ran the ball during last Sunday's 23-20 win at Chicago. He also explores the idea of playing until age 40 and likes being an inspiration to younger running backs.

There is a reason why kicker Blair Walsh has gotten so many chances to get his groove back. The Vikings have one of the NFL’s least productive offenses when it comes to scoring touchdowns inside the red zone.

They have scored touchdowns on only 38.1 percent of their trips inside the 20-yard line this season, which ranks 30th in the league.

Offensive coordinator Norv Turner said the biggest issue has been running the ball ineffectively, especially when the Vikings approach the goal line.

“We’ve tried to run the ball in there, and through a stretch of four or five possessions in there, we had situations that kept us from running the ball, whether it was someone getting beat, it was a mental error, whether it was a miscommunication,” he said. “We need to run the ball better.”

Despite their problems with red-zone running, the Vikings continue to give the ball to Adrian Peterson, especially on first down. They have had a first-down play in the red zone 25 times. They have run the ball on 22 of them. Nine of those runs went for a loss or no gain.

“Execution is way, way heavier in my thinking than tendencies,” Turner said.

Vikings running back Adrian Peterson (28) with a second quarter gain Sunday afternoon.

Keep it moving, buddy

Instead of pointing fingers after getting taken down in the backfield far too often against Kansas City and Detroit, Peterson decided to take a closer look at himself. He realized on several carries he stopped his feet in the backfield as he tried to shimmy, shake and make defenders miss.

So at Chicago on Sunday, Peterson made a conscious effort to keep moving downhill. He believes that was a big factor in his productive day, though a pretty strong effort from the offensive line helped, too.

“Coming back and watching the [Bears] game, it was like, ‘Wow, that’s how you used to run the ball,’ ” he said. “You take away your power by stopping your feet and trying to do too many moves.”

Sunday, only four of his 20 carries went for 2 yards or fewer. He ran for 103 yards, his first 100-yard outing since Week 3.

Diggs back at practice

Wide receiver Stefon Diggs, who missed Wednesday’s practice because of a hamstring injury, returned to practice Thursday as a limited participant.

Center Joe Berger (chest) was also back at practice on a limited basis.

Safety Harrison Smith was added to the injury report. He has a neck injury and was listed as a limited participant.

A trio of other defensive starters remained sidelined: linebackers Anthony Barr (lower back) and Eric Kendricks (ribs) and defensive tackle Sharrif Floyd (knee).

Fusco is ‘up and down’

Brandon Fusco so far has struggled with the transition from right guard to left guard. No Vikings offensive lineman has allowed more pressure on the quarterback than Fusco, according to Pro Football Focus. And Fusco has been a negative player in the running game as well.

“It’s a little bit of knocking the rust off and a little bit of playing a different position,” offensive line coach Jeff Davidson said. “But a lot of it is just making sure he gets it through in his head to understand the role he is trying to play on our team and finding a way to shine in that role.”

Fusco acknowledges that his play has been “up and down” this season.

“I’ve struggled a little bit. I know I haven’t played my best,” the veteran said. “So for me, it’s just coming into work and improving every day.”

Special teams trickery

Not only do the Rams have one of the NFL’s most feared punt returners in Tavon Austin, they also mix in a variety of fake and trick plays under special teams coordinator John Fassel, the son of former Giants coach Jim Fassel.

“Going to be a lot of sleepless nights this week,” said special teams coordinator Mike Priefer, as he prepares for St. Louis on Sunday. “[On punts], they’ve got different formations, they run fakes, their punter can throw the ball. … They’ll run a surprise onside kick. [On] kickoff return, they’ve run reverses. So we have our work cut out for us.”