What it means: The Vikings are now 1-4, and after a tumultuous week that included a quarterback change and a tragic turn of events for Adrian Peterson, the team looked as lost and as listless as it has all season. Injuries didn't help -- the Vikings lost Desmond Bishop, Xavier Rhodes and Harrison Smith to knee, ankle and foot injuries, respectively -- but Matt Cassel squandered the goodwill he'd created two weeks ago in London and might have paved the way for Josh Freeman to take over at quarterback. That might be all Vikings fans have to look forward to at this point.
Stock watch: Falling -- Vikings' defense. It couldn't have been much lower, for a team that was 30th in the league heading into Sunday. But Minnesota let a 1-3 team control the game from the beginning, and spent nearly 36 minutes on the field. Josh Robinson got burned on a 79-yard touchdown just after halftime that looked like a coverage mix-up with Rhodes, and the Vikings briefly pulled him from their nickel package before Rhodes' injury forced them to put him back. The defensive line couldn't sustain pressure on Cam Newton, and as much intrigue as there is about the Vikings' QB situation at the moment, their defensive issues -- particularly the ones in the secondary -- might be a bigger concern.
Peterson quiet: The reigning NFL MVP was on the field just two days after his 2-year-old son died from injuries sustained in an alleged aggravated assault in South Dakota, but Peterson was held in check by the league's No. 3 defense. He had just 10 carries -- which tied for the fifth fewest of his career -- and ran for 62 yards, catching another three passes for 21 yards. Peterson had just four carries in the first quarter that went for minus-1 yards.
Cassel struggles: Two weeks after leading the Vikings to their only victory of the season, Cassel threw two interceptions in the loss to the Panthers, overshooting receivers on both picks, and couldn't lead the Vikings on a touchdown drive until he connected with Kyle Rudolph in the final two minutes. He completed 32 of 44 passes for 241 yards, but was forced to throw 25 times in the second half with the Vikings in a big hole. His turnovers were the major issue, and it will be interesting to see whether the Vikings try to get Freeman ready for next Monday's game against the New York Giants.
What's next: The Vikings (1-4) travel to New Jersey for a "Monday Night Football" matchup against the 0-6 New York Giants.