ST. LOUIS -- The Vikings open the preseason tonight against the St. Louis Rams at the Edward Jones Dome.

We'll have more later when we arrive at the stadium, but while we're waiting here are a few thoughts heading into the game.

Don't expect the starters to play long. Coach Brad Childress said they will only play a series or two. Tarvaris Jackson will run the first-team offense so that means Sage Rosenfels will get extended playing time with rookie Joe Webb likely playing the fourth quarter. Judd wrote about Rosenfels today and what he hopes to get out of preseason games.

We know for sure that Sidney Rice and Percy Harvin won't play. I can't imagine center John Sullivan will play either after missing considerable time in camp with a calf injury, but our understanding is that he feels much better and is likely close to returning to the field for a full practice.

We don't know how much work Adrian Peterson will get, if any at all. Peterson was bothered by tightness in his left hamstring in camp so it wouldn't be surprising if they hold him out.

I'm interested to see if the coaching staff lets middle linebacker E.J. Henderson see some action. Henderson has made a faster-than-expected recovery from a broken left leg and he wants to play tonight. But as of Thursday afternoon Childress said no decision had been made.

This obviously is an important night for the rookies and young players who are trying to make an impression. I'm interested to see how Toby Gerhart, Chris Cook, Chris DeGeare and others perform in their first NFL game. Cook and DeGeare have been particularly impressive in camp so the Vikings want to see how that carries over to game situations.

A handful of young receivers are competing for one, maybe two, roster spots so they need to showcase themselves. That group includes Jaymar Johnson, Logan Payne, Ray Small and Taye Biddle.

Finally, we know that Brett Favre had a checkup with Dr. James Andrews in Florida this week. Fans and reporters caught wind by tracking a private plane that carried Favre to Florida.

Turns out, a Florida Atlantic baseball player had an appointment with Andrews that day too and saw Favre as he sat in the waiting room. Here is a blog item from FAU about it. The pitcher put on his reporter's hat and tried to get some info from Andrews on Favre's ankle but didn't get answers.