The Pittsburgh Steelers open 2020 NFL training camp on July 28 at Heinz Field. Here's a closer look at a few storylines:

Will Ben Roethlisberger's return be the catalyst for JuJu Smith-Schuster and James Conner to have bounce-back seasons?

Without Roethlisberger, the Steelers' offense was stilted and toothless last season. Defenses weren't convinced in the ability of backups Mason Rudolph and Devlin Hodges to throw the ball downfield. The pair ranked last in the NFL for average completed air yards at 4.5, allowing defenses to load up the box to stuff the run.

Although the Steelers averaged 90 rushing yards per game in 2018 and 2019, yards per carry dropped to just 3.7 last season, down from 4.2 the year before. Roethlisberger's return will force defenses to defend the pass and free up room for running back James Conner to work. And while JuJu Smith-Schuster will definitely benefit from Roethlisberger's return, the bigger catalyst to a bounce-back season will be the emergence of a solid No. 2 receiving threat. That guy could be Diontae Johnson, Eric Ebron or rookie Chase Claypool. Though Roethlisberger led the NFL in passing yards in 2018, his completed air yards per attempt was only slightly better than Rudolph and Hodges' at 4.8.

But as the No. 2 receiver to No. 1 Antonio Brown, Smith-Schuster had a Pro Bowl season with 111 receptions, 1,426 receiving yards and seven touchdowns. Without Brown, Smith-Schuster was targeted far less last season -- just 70 times -- but that was due to a combination of factors: his health, lack of consistent receiver support and quarterback instability. Roethlisberger has a proven chemistry with Smith-Schuster, but his return alone can't spark a comeback for the fourth-year receiver.

How will the Steelers' defense evolve with the losses of Javon Hargrave and Mark Barron?

Losing defensive tackle Hargrave and linebacker Barron hardly dooms the Steelers' defense, but it does make the margin for error razor thin. Hargrave was the most valuable when Stephon Tuitt landed on IR midway through the 2019 season with a torn pectoral muscle. He was strong in the pass rush with four sacks, but he isn't irreplaceable. Hargrave's most important snaps of the season came as Tuitt's replacement, and if Tuitt and Cameron Heyward stay healthy, Hargrave would have moved back to his primary role at nose tackle. But the Steelers rarely use the 3-4 base defense featuring a traditional nose tackle.

"A traditional 3-4 nose tackle, again, I don't want to say it's dying, but it's less and less of base defense," Steelers general manager Kevin Colbert said earlier this year. "When you're in a defense 75% of the time, different sub-packages, I don't know if anyone has a base defense even though you do say you're a 3-4."

The Steelers will still have a player filling Hargrave's old role if needed -- coach Mike Tomlin said veteran Tyson Alualu will get the first snaps at nose tackle in training camp. But without Hargrave, the Steelers will continue to utilize their signature sub-packages.

In cutting Barron, the Steelers will rely far more on Devin Bush and Vince Williams. Bush had a solid rookie season, playing 80% of the snaps, and he could see even more in 2020.

Other than Roethlisberger, Bush's health will be one of the biggest determining factors of the Steelers' success this season. He'll have help from Williams at inside linebacker, but because the Steelers didn't add to the position with a significant free agency signing or draft pick, the other backup will come from two players who have one combined defensive snap of experience.

What is a realistic expectation for the Steelers this season?

It's realistic to think the Steelers can return to the playoffs after a two-year hiatus. Assuming Roethlisberger is able to play all or most of the season and Smith-Schuster and Conner stay healthier than a season ago, the Steelers are in a good position to win at least nine or 10 games. They're still chasing the Ravens to be the best of the AFC North, but with a healthy team, they should have an edge on the Cleveland Browns and Cincinnati Bengals. With each of those division rivals breaking in either a new coaching staff or a new quarterback, the Steelers' continuity gives them a significant advantage in a season altered by the COVID-19 pandemic.

If they don't make the playoffs, is coach Mike Tomlin on the hot seat?

In another organization, maybe. But the Steelers have only had three head coaches since 1969. If Tomlin was fired after this season, he would be the shortest-tenured Steelers head coach at 14 seasons. Bill Cowher was there for 15 before retiring, and Chuck Noll lasted 23 years. At different points during their tenures, Cowher and Noll missed the playoffs for three or more consecutive seasons. If the Steelers miss the playoffs this season, it will be the first time Tomlin has missed them in three consecutive years. The Steelers also haven't missed the playoffs because of his coaching performance.

Under Tomlin's leadership, the Steelers almost made the playoffs despite losing Roethlisberger in Week 2 and dealing with injuries to Smith-Schuster and Conner. The success of this season hinges largely on Roethlisberger's ability to return to form after his elbow surgery, and if his comeback doesn't go as planned, it shouldn't affect Tomlin's job status. The Steelers would likely give him a couple more years with a new quarterback before making any changes.