The Falcons take their “toughness crusade” to the field against the Miami Dolphins for their exhibition opener at 7 p.m. Friday at the Georgia Dome.

The Falcons have had a spirited training camp, with several fights, scuffles and brawls, as their toughness has been repeatedly questioned after last season’s 4-12 record. The theme has been “tough, smart football” for 2014, as shown on HBO’s “Hard Knocks.”

While the starters are not expected to play much, there will be several things to keep an eye on as the Falcons try to become a more tenacious team in the trenches.

Here are five things to watch against the Dolphins:

1. The pass rush. The Falcons are banking on a stouter defensive front to wear down the interior of lines. If the pocket is collapsed, the outside rushers and linebackers should have better pass-rush lanes.

Defensive coordinator Mike Nolan was not pleased with rookie Ra’Shede Hagemen’s showing at Friday Night Lights last week, but said he’s having a good camp. Defensive tackle Paul Soliai and defensive end Tyson Jackson, both key free-agent signees, have played well.

“Malliciah (Goodman), although not a first-year guy, has made a lot of progress,” Nolan said. “He is worth mentioning. He is a guy you need to watch because he has done a good job.”

Goodman is up to 290 pounds after playing at 276 last season.

The Falcons expect Hageman’s progress to occur gradually.

“He has got time with the guy in front of him,” Nolan said. “He can also learn a lot from Tyson. Tyson is a very intelligent player and he has great communication skills, so that helps the young guys behind him.”

2. The linebackers. The Falcons believe they have a keeper in linebacker Prince Shembo, who moved to inside linebacker. He'll get plenty of action against the Dolphins.

“Shembo has been a pleasant surprise,” Nolan said. “He is a position-change guy from college, so it’s not totally natural where he is playing right now. But he is a 100 percent-willing type of guy.”

Nolan said Shembo has embraced the change.

“He takes it really serious,” Nolan said. “He is a real intense guy on the field. It’s hard to break him away to get his attention on things because he is so intense. He works extremely hard. He is tough.”

The Falcons like his size (258 pounds) and speed, but he may not be ready to contend for a starting spot right away.

“I do believe he is going to continue to get better,” Nolan said. “He is wearing a lot of hats. We are playing him at both the inside linebacker positions and only because he can handle it mentally. We are trying to challenge him mentally to see, but he does a good job with that.”

3. Backup QB T.J. Yates. With starting quarterback Matt Ryan expected to play one series, T.J. Yates and Sean Renfree will get the bulk of the action against the Dolphins.

The Falcons made a late-offseason trade for Yates, and the former Pope High standout has had to play catch-up. He is still learning the nuances of the system.

“We have to remember that T.J. has only been here, today was practice 12,” offensive coordinator Dirk Koetter said Thursday. “T.J. handles himself very well in the huddle.”

“Renfree has been in all those meetings for the last year and half,” Koetter said. “He’s watched Matt run the show. Sean is off to a fast start. He’s looked sharp out there.”

Jeff Mathews, a record-setting quarterback from Cornell, has impressed, too.

“Jeff can throw the ball. Man can that guy spin it,” Koetter said.

4. The tight ends. Levine Toilolo will get a lot of attention as he gets the first chance to replace the great Tony Gonzalez, who retired after last season.

“There are some interesting battles going on within the tight end group,” Scelfo said. “All five of those guys are battling. It’s a different role for those guys than what we had in the past with Tony. They are doing everything that we’re asking of them.”

5. The free safeties. With Dwight Lowery recovering from a concussion and third-round pick Dezmen Southward coming back from a knee injury, third-stringers Kemal Ishmael and Sean Baker should get extensive action against the Dolphins.

The Falcons are trying to replace Thomas DeCoud, who was released this offseason, and the injuries to Lowery and Southward have muddled the competition.

Ishmael, a second-year player drafted in the seventh round in 2013 out of Central Florida, has shown flashes of spectacular play.

“Kemal has had a good camp,” Nolan said. “He is one of the guys who has been able to take advantage of the front line being stouter, just from the standpoint of coming up and closing the gap.”

Baker has “stepped up his game,” Nolan said. He intercepted a pass thrown by backup Renfree in Wednesday’s practice.