Two teams who have experienced as much change as any in the NFL the past few weeks open their preseason Thursday night at Lincoln Financial Field.

The Philadelphia Eagles have been frequent shoppers in free agency, assembling an all-star cast that has led some to call them the NFL's Dream Team.

The Ravens, meanwhile, have yet to come up with a nickname. Fans are still trying to remember some of their names.

A salary-cap purge combined with several injuries has forced the Ravens to field a more inexperienced team than anyone anticipated, especially on the offensive side. While Joe Flacco is expected to be play only the first quarter, it should be an interesting one considering the four new 20-something starters (wide receiver Torrey Smith, tight end Dennis Pitta, center Bryan Mattison and right tackle Oniel Cousins) surrounding him.

"We have guys that are playing for the first time, so we are going to have to really see what they are all about and what they are made of," Flacco said. "I think these guys have it. These guys have to go out there and play with confidence. We have to trust it, and I have to trust that they are going to do that and see if they can make some plays, see if we can make some plays as a unit."

For the first time in his NFL career, Flacco isn't throwing the ball to Derrick Mason and Todd Heap, who were released to create cap room two weeks ago. Instead of targeting the top two receivers in franchise history, he will be looking for a rookie second-round pick in Smith and an unproven tight end in Pitta (who is filling in for the injured Ed Dickson).

Flacco also isn't taking snaps from center Matt Birk. With the six-time Pro Bowl player out at least a couple more weeks with a knee injury, Flacco is getting the ball from the son of former defensive coordinator Greg Mattison.

The other unsettled spot on the offensive line is at right tackle, where Oniel Cousins (four career starts) and rookie third-round pick Jah Reid are battling for the job.

When Flacco breaks the huddle, only two offensive starters — left guard Ben Grubbs and right guard Marshal Yanda — will be able to say they've been with the Ravens longer than the fourth-year starting quarterback.

"He really relishes the pressure," offensive coordinator Cam Cameron said. "I've been around very few guys who embraced the pressure. When it works out, he gives credit to everybody else. When it doesn't work out, he walks in with his head high and takes it like a man and moves on. There are a lot of guys who can't do that. There are so many reasons he's special and that's one of them."

Cameron called this the most important preseason game in his coaching career. With the lockout eliminating offseason minicamps and NFL rules delaying the return of restricted free agents, the Ravens are going into this game after only seven days of practice with the entire team.

Ravens coach John Harbaugh said the offense took a step back on Saturday during the open practice at M&T Bank Stadium. But it rebounded with solid workouts on Monday and Tuesday.

Rookie sixth-round pick Tyrod Taylor is scheduled to take over for Flacco and play for 2 ½ quarters. Hunter Cantwell, a practice squad quarterback last season, is expected to get a half-quarter of work.

"It's going to be very interesting to see where we're at," Harbaugh said.

The Ravens' offense isn't the only group going through changes. This marks the debut of new defensive coordinator Chuck Pagano.

While he has promised a new aggressive style, he said to expect the Ravens to be "pretty vanilla" on defense in the preseason.

"We're not coming after them every snap," Pagano said. "There are some things we definitely don't want to show leading up to the opening game.

"We're going to see who can play football. We're going to see who can take on a block, who can get up and get off a block, tackle, make plays in the pass game."

Pagano added, "Now that doesn't mean we're going to sit back and just let them shoot fish in a barrel, either."