The Bears close their preseason by hosting the Cleveland Browns Thursday night at Soldier Field. Here are four things to watch in the game:

(1) How will rookie quarterback Mitchell Trubisky fare in his first pro start?

Rookie quarterback Mitchell Trubisky is slated to start Thursday night's preseason finale.

While most key players across the NFL traditionally sit out the preseason finale, the Bears will start Trubisky because the chance to get the second overall pick in the draft more game experience is simply too good to pass up. "It's not easy to get live game reps as a quarterback in this league," said coach John Fox. "It helps development. He needs all those opportunities he can get and no different Thursday night."

Trubisky has outperformed most realistic expectations in the Bears' first three preseason games, completing 70.8 percent of his passes (34 of 48) for 354 yards with three touchdowns, no interceptions and a 112.7 passer rating. The North Carolina product has also shown the ability to scramble, gaining 47 yards on four runs.

With veteran free-agent acquisition Mike Glennon seemingly entrenched as the Bears starting quarterback after an impressive performance last Sunday in Tennessee, Thursday night represents the last expanded playing time that Trubisky sees for a while.  Connor Shaw is due to relieve Trubisky against the Browns, while Glennon and veteran backup Mark Sanchez both are not expected to play.

(2) Will rookie tight end Adam Shaheen make an impact?

While fellow rookie draft picks Trubisky and running back Tarik Cohen have both flashed their ability this preseason, Shaheen so far has been unable to transfer what he has shown on the practice field into games. The second-round draft pick from Ashland University has just three receptions for 18 yards.

A man among boys at the Division II level, Shaheen has dominated at times in practice, especially in the red zone, where the 6-6, 270-pounder has taken advantage of his ideal combination of size, athleticism and excellent hands. But he hasn't made much of an impact in the first three preseason games.  

Shaheen figures to get plenty of opportunities to impress in the preseason finale. He needs to show the Bears that he's capable of not only getting into the end zone like he did last year when he set a Division II record for tight ends with 16 TD catches, but also that he's a capable blocker, something he wasn't asked to do very much in college.

(3) Will undrafted rookie receiver Tanner Gentry continue to excel?

Everyone loves to root for an underdog and this year in Bears camp it's been Gentry, who went undrafted despite catching 72 receptions for 1,326 yards and 14 touchdowns during a breakout senior season last year at Wyoming.

Gentry clearly has a chip on his shoulder and produced more long receptions than any other receiver in camp. He's developed a nice rapport with Trubisky, a chemistry that was evident last Sunday against the Titans when they connected on a picture-perfect 45-yard TD pass down the left sideline.

With top receiver Cameron Meredith out for the season after tearing his ACL in Tennessee, the Bears will need their entire receiving corps to help fill the void. Gentry could be one of those players if he continues to perform as well as he has throughout the summer. He likely will see expanded playing time Thursday night against the Browns and hopes to convince that he's capable of becoming a regular contributor on offense and special teams.

(4) Will pro Roy Robertson-Harris keep producing impact plays?

The Bears switched Robertson-Harris from outside linebacker to defensive end this offseason and the move is paying dividends. The second-year pro from UTEP recorded sacks on back-to-back plays against the Cardinals and then blocked a punt that rolled out of the end zone for a safety versus the Titans.

Robertson-Harris has bulked up to 290 pounds and is thriving after missing all of his rookie season last year with an undisclosed illness. "Last year was kind of a difficult time," Robertson-Harris said recently. "My wife had just had our son, so I was a new dad. Being in the league for the first time, going through a bunch of changes; not being able to play your first year is kind of difficult. I kind of went through a deep depression. This year's pretty exciting. I've been able to make some plays in practice and games."

With the Bears expected to rest most of their regulars Thursday night as is customary in the preseason finale, Robertson-Harris will have another chance to prove he deserves a spot on the team's 53-man roster.