LONDON – Fan criticism and questions about his poor play followed Christian Ponder 4,000 miles to another country. But a different, unexpected topic also came up before the Vikings conducted their first practice abroad Wednesday.

Coach Leslie Frazier disclosed that Ponder suffered a rib injury early in Sunday's 31-27 loss to the Cleveland Browns. Ponder was limited in practice and his availability for Sunday's game against the Pittsburgh Steelers is unclear at this point.

Frazier said he needs to evaluate Ponder in practice the next few days before making a determination. If Ponder is ruled out, veteran Matt Cassel will see his first action in a Vikings uniform.

"My mind-set is we're going to do what's best for the team," Ponder said. "If I can't perform my regular duties, then Matt is going to step in and play."

Ponder didn't miss any time in Sunday's game after taking the hit, but he indicated that an additional examination revealed his injury. He declined to give specifics about the exact nature of his injury.

"I wasn't sure how serious it was and kind of played through it and was fine," he said. "I got the news yesterday morning that it was injured."

Christian Ponder played catch with his backup, Matt Cassel, during the Vikings’ first practice in London on Wednesday.

If he plays, Ponder said his primary concern would be taking contact to that area. He said the equipment staff will outfit him with added protection. He was able to throw passes Wednesday, which he described as "a little uncomfortable, but it's manageable."

"We're going to push it to the limit and see what we can do in a smart way," he said. "My mind-set is I want to play this game, and I'm going to do everything possible to do so."

Cassel said he learned of Ponder's injury Wednesday. He will take additional reps in practice in case he gets the nod.

"Christian's a tough kid," Cassel said. "I don't know his situation or how it's going to go, but I've got to prepare like I'm going to play."

Ponder's injury only adds to his inauspicious start to the season. Vikings fans booed him throughout Sunday's loss and started a loud "Cas-sel" chant at one point. In three games, Ponder has thrown only two touchdown passes and accounted for seven turnovers (five interceptions and two fumbles). His 65.9 passer rating ranks 30th among starting quarterbacks.

Given the barrage of criticism Ponder is feeling at present, one British reporter asked him to explain what it's like being an NFL quarterback.

"It's fun," he said, drawing laughs. "I've wanted to do it ever since I was a kid. There are some negative lights to any job. And things come with the territory. But this is what I've wanted to do ever since I was a kid. There's a lot of responsibility, but it's a fun game to play and it's a fun position."

That prompted another reporter to ask Ponder if he believes the popularity of fantasy football has elevated the scrutiny of quarterbacks.

"I think fantasy football is an interesting deal because everybody has their stake in what goes on," he said. "There's a lot of money in fantasy football so when mistakes happen that affect fantasy points, you're going to hear it. I think that's for any position, not necessarily just quarterback."

So, Christian, do you play fantasy football?

"I do not play fantasy football, no," he said.

The Vikings are more concerned with reality football and whether Ponder can turn his season around and show that he can succeed long-term at that position. General Manager Rick Spielman gave a rare in-season media briefing Wednesday, but he deflected a question about Ponder.

"I don't want to get into evaluating personnel at this point," he said. "I always want to sit back and take a grand picture of it and evaluate and assess it at the end of the year. I write up reports on our players every week, but I'm not going to sit here and comment directly on a player — he's doing this or that. I will do that at the end of the season when we make our final assessments."