Upon Further Review: Vikings Week 4

LONDON -- An examination of four hot issues following the Minnesota Vikings' 34-27 win over the Pittsburgh Steelers:

Who's the QB? That will be the Vikings' big question during and after their bye week, as they prepare for their next game against the Carolina Panthers on Oct. 13. Coach Leslie Frazier said Sunday, "If you're asking, our quarterback is Christian Ponder," even after Matt Cassel threw for 248 yards and a pair of touchdowns in the Vikings' first win of the season. Players such as Greg Jennings and Adrian Peterson have stood by Ponder in his struggles, but even those two seemed relieved to be praising, instead of defending, their quarterback after Sunday's win. Frazier will have to gauge how his team would react to a return to Ponder, and Cassel's struggles the past two years in Kansas City are proof he has had his own issues. But it will be interesting to see how Frazier navigates the next two weeks and how his players will react to whatever decision he makes.

Peterson emerges: The numbers would suggest Peterson hadn't played poorly in three games before Sunday -- he had still run for 281 yards in three games -- but the NFL's reigning MVP hadn't looked like himself until heading to London. With fullback Jerome Felton back, Peterson seemed more comfortable, romping for 140 yards in the Vikings' win. His 60-yard run in the first half was actually set up by quarterback-turned-receiver Joe Webb, who sealed off safety Troy Polamalu after seeing something on a previous play. "He came to me on the sideline," Peterson said. "He was telling me, 'Hey, on the 42 Lead, Troy [Polamalu], the safety, is cramming in, and he's shooting right down. So just trust me on being able to pin him in. You can get it outside.' And sure enough, the next time we caught it, it happened exactly the way he was playing."

Secondary struggles: The Vikings won, and they survived without Chris Cook and Jamarca Sanford, but those facts probably won't dampen concerns about their defensive backs after the Vikings allowed more than 300 yards passing for the third time in four weeks. Steelers quarterback Ben Roethlisberger had to throw on almost every play in the fourth quarter with Pittsburgh down 17, but he targeted second-year cornerback Josh Robinson throughout the game, and Robinson added a 48-yard pass interference penalty to the Steelers' production for the day after he grabbed Antonio Brown and put the ball at the Vikings' 1.

London calling ... again? This won't emerge as a front-burner topic for a while, but it wouldn't be surprising to see the Vikings back in London before they open their new stadium in Minneapolis in 2016. Vikings players gushed about the accommodations the team had at The Grove Hotel in Watford, England, and Frazier spoke glowingly about the experience after the Vikings won at Wembley Stadium on Sunday and lifted a little pressure off themselves before their bye week. Before the game, team officials privately weren't keen on the idea of coming to London as the home team again and taking players out of their routine for a week in addition to giving up a home game. But it will be interesting to see if the Vikings have different feelings now that they've seen a week in London is manageable. Frazier is a big believer in settings like these, which encourage team bonding, and if the London trip emerges as a turning point in the season, you can bet the Vikings will consider doing it again. With the team at the University of Minnesota's TCF Bank Stadium in 2014 and 2015, the NFL is likely to ask.