After eight long months, the Bears finally return to game action Thursday night when they open the preseason by hosting the Denver Broncos at Soldier Field. Here are three storylines to watch:

(1) The debut of quarterbacks Mike Glennon and Mitch Trubisky.

Preseason opener

The Bears completely revamped the most important position on the field after a disappointing 3-13 season, signing veteran free agents Glennon and Mark Sanchez and trading up one spot in the draft to select Trubisky with the second overall pick—their highest since 1951.

The plan for this season is to start Glennon and to groom Trubisky as the franchise’s quarterback of the future. That means Glennon will lead the No. 1 offense against the Broncos, looking to build on his performance in last Thursday night’s Family Fest practice at Soldier Field.

On the first-team’s only possession in a live scrimmage in that workout, Glennon engineered a nine-play, 60-yard touchdown drive by completing 5 of 5 passes for 53 yards, including an eight-yard TD strike to tight end Dion Sims, another key free-agent acquisition.

“[Glennon] is making good decisions,” said coach John Fox. “He’s put a lot of extra time and effort into the playbook, understanding our system. He’s done a good job of developing a chemistry with his teammates. I’ve liked what I’ve seen thus far.”

Trubisky, meanwhile, is expected to follow Glennon and Sanchez into Thursday night’s game and work with the No. 3 offense as he has done for the majority of training camp.

Asked what would constitute a successful outing for him, Trubisky said: “Doing my job, helping my teammates do their job, taking care of the football, driving the ball down the field, just being efficient, getting completions and going out there and having fun.”

(2) Whether a revamped secondary can help the defense start generating takeaways.

It’s only a preseason game, but Thursday night would be a great time for the Bears defense to start creating more turnovers. After producing an all-time franchise-low 11 takeaways last season, general manager Ryan Pace revamped the secondary by signing cornerbacks Prince Amukamara and Marcus Cooper and safety Quintin Demps in free agency and selecting safety Eddie Jackson in the fourth round of the draft out of Alabama.

There’s a chance that all four could start in the season opener, though Jackson would have to supplant third-year pro Adrian Amos. After being limited during offseason workouts while recovering from a broken leg he sustained last season with the Crimson Tide, Jackson has shown excellent ball skills, instincts and range in training camp. On two separate occasions, he dashed from the middle of the field to the sideline to make a leaping interception.

Jackson had a knack for finding the end zone on both defense and special teams the past two seasons at Alabama, scoring three touchdowns on interception returns of 50, 93 and 55 yards and two TDs on punt returns of 85 and 79 yards.

Demps brings veteran leadership to the secondary, not to mention ball skills. His six interceptions last year with the Texans were just two fewer than the Bears mustered as a team in 2016.

“Demps has done a nice job,” said defensive coordinator Vic Fangio. “He’s picked up the defense pretty good, does a good job of reacting and keying things and pulling his trigger. Just have to see him finish plays, which we’ll be able to see in games.”

(3) How playmaking rookies Adam Shaheen, Tarik Cohen and Tanner Gentry impact the offense.

All three promising young prospects have consistently made big plays in practice and will look to carry their success over into the preseason against an actual NFL opponent.

Shaheen has made the transition from tiny Ashland University to the NFL a smooth one to this point, demonstrating the same pass-catching ability that enabled him to set a Division II single-season record for touchdown receptions by a tight end last year with 16.

The 6-6, 270-pounder possesses ideal NFL size, excellent hands and is honing his skills as a blocker after not being asked to focus much on that aspect of the game in college. Shaheen is a dangerous red zone threat, something he displayed in a recent practice when he leaped over Demps to make a one-handed catch of a fade pass from Glennon.

Cohen has electrified the fans at training camp on a regular basis with an array of moves that earned the running back the nickname “The Human Joystick” while starring at North Carolina AT. The diminutive 5-6, 181-pounder was both flashy and productive in college, becoming the all-time leading rusher in Mid-Eastern Athletic Conference history with 5,619 yards.

The Bears project Cohen as a third-down “joker” back who can create mismatches with defenses. He’s also in contention for the punt-return job. The only punt he returned in college went for a 67-yard touchdown last season, but it was nullified by a penalty.

Gentry, a receiver from Wyoming, has been the most impressive undrafted rookie in camp. After catching a 46-yard pass from Mark Sanchez deep down the right sideline in Monday’s practice, Gentry had three touchdown receptions in Tuesday’s workout—on a one-handed catch and a sliding grab from Sanchez and a long pass from Trubisky.