Matt Cassel gets another shot as the Vikings' starting quarterback this week in place of Christian Ponder, who still is experiencing concussion symptoms. The reigning Super Bowl champion Baltimore Ravens (6-6) have struggled offensively, but they're still tough at home. Here are three things to consider as the teams prepare for Sunday's matchup:

1. Ravens running game has bogged down

The Ravens are tied for 29th in the NFL in rushing this season, and running back Ray Rice has received considerable criticism for their ineffectiveness. Ray has rushed for only 482 yards on 2.9 yards per carry.

Rice suffered a hip injury early in the season, but he's reportedly close to healthy now. The offensive line also has struggled to consistently create holes for Rice and backup Bernard Pierce.

As a team, the Ravens have rushed for 100 yards in a game only two times.

"The biggest issue is we don't seem to be getting any yards," Ravens coach John Harbaugh joked on a conference call. "All the other issues add up to that. I think it's always a compilation of a lot of things. We certainly don't have the running game that the Vikings have. We envy that running game. But we have not been able to get that done like we want to so far this year."

2. Carlson is making the most of his opportunity

Tight end John Carlson had a miserable first season with the Vikings in 2012. He suffered an injury in training camp and never became a factor in the offense, finishing with only eight catches for 43 yards and zero touchdowns.

Carlson had a minimal role through the first eight games this season until Kyle Rudolph suffered a fractured foot. In his absence, Carlson has produced the second-most receiving yards by an NFL tight end the past four games, trailing only New England's Rob Gronkowski.

Carlson has caught 19 passes for 264 yards and one TD in place of Rudolph, who still is sidelined.

"It's been fun to feel like I'm contributing," Carlson said. "Last year obviously didn't go the way I wanted it to go. Everyone wants to feel like they're contributing and doing their part to help the team win. When you're not even on the field or if you're in there and you're not doing what needs to be done, that's not where you want to be. So it's been fun to have a chance to make some plays in the pass game."

3. Williams gets kudos from teammates

Defensive tackle Kevin Williams was selected by teammates as the Vikings Ed Block Courage Award recipient. An 11-year veteran and the team's oldest player at age 33, Williams has missed only three games because of injury in his career. He's started 167 games, a team record for a defensive tackle.

"You can't make plays and you can't be counted on if you can't show up," Williams said.

The Ed Block Courage Award honors one player from every team who "exemplifies commitment to the principles or sportsmanship and courage."

Williams' contract expires at the end of the season. He has indicated that he would like to play a few more seasons with the Vikings, but he said he's taking time to appreciate what might be his last run with the organization.

"Coming in as a rookie you're bright-eyed and bushy-tailed and you never know what to expect," he said. "It takes three or four years for you to actually realize this is a billion dollar business. Each team does everything it can to win. It's nothing personal, but it's all business. You have to soak up all the moments you can. The wins, enjoy the playoff runs, embrace all the people you meet and the friends you make, because one day it's going to eventually be done. Right now we're just trying to play ball, enjoy the group I'm with and we'll see where we go at the end of the year."