1. Mike Glennon
Glennon is, for now, the Bears’ unquestioned starting quarterback — a role the Bears made clear he wasn’t going to lose after drafting Mitch Trubisky with the second overall pick in April. It would take a monumental effort from Trubisky — and a disappointing one from Glennon — for that to change. But Glennon has only attempted 11 more passes in the NFL than Trubisky since the beginning of the 2015 season, leaving plenty of uncertainty heading to Bourbonnais. Glennon’s three-year, $45 million contract is structured so the Bears could cut him for $2.5 million next spring, and with a highly-touted player developing behind him, he may not have as much leeway as his contract would appear to give him. As Glennon put it in May: “This is my year. There are no guarantees in the NFL.” The 27-year-old is well aware this year is his best opportunity to prove, either to the Bears or the rest of the league, that he’s capable of being a successful starting quarterback. That process begins in earnest this week.
2. Mitch Trubisky
While it remains unlikely that Trubisky will be the Bears’ Week 1 starter, if he proves to be better than Glennon at the end of August…why would he not be the starter? It’s not a simple yes or no question, given Trubisky has to learn a largely different offense than the one he ran in college (unlike Philadelphia’s No. 2 pick, Carson Wentz, a year ago) and only started 13 games since leaving high school in Mentor, Ohio. But it’s the job of John Fox and his coaching staff to win games, and if they come to a consensus that Trubisky gives them a better chance of winning, then it would make sense for him to start. What’s more likely in reach for Trubisky during training camp is showing enough to the coaching staff to lay the foundation for him to play in 2017, either as a substitute or as a starter later in the season.
3. Kevin White
Aside from the quarterbacks, it’s hard to think of a player with more to prove than White. It’s too early to label White a bust, given those two leg injuries limited him four games in his first two years, but the Bears at least need him to be healthy this year to start to figure out what they have in the former seventh overall pick. White was targeted 36 times before suffering his season-ending injury last year and averaged 5.19 yards per target, which was the third-lowest average among receivers with at least 35 targets in 2016. That's surprising for a guy who was drafted with such good speed, so not only will White have to prove he can stay healthy, but he'll have to prove he can be more productive within the Bears' offense.
4. Leonard Floyd
NFL
While White may have the most to prove, Floyd probably has the highest expectations placed upon him in 2017. Floyd’s 7 1/2 sacks last year were promising, and he appears to be past the scary post-concussion malaise he suffered in January and February. If Floyd grows into a double-digit sack guy for the Bears this year, he could be the catalyst for some significant improvements for the entire defense (a better pass rush begets more opportunities for interceptions, etc.). But he’ll also have to prove the issues that led to those two concussions last year — chiefly, poor tackling form — are a thing of the past, and that he’s able to make that Year 1 to Year 2 leap the Bears think he can.
5. Kyle Fuller
Fuller faces an uphill climb to make the Bears’ 53-man roster, so what he’s trying to prove may be of more value to finding a post-Chicago landing spot. Vic Fangio’s pointed comments about Fuller’s willingness (or lack thereof) to play last year cast doubt on his future, but he’s still still here after being neither cut nor traded in the offseason. The Bears declined Fuller's fifth-year option earlier this year, though, so training camp may be Fuller's last chance at sticking in the NFL, either with the Bears or elsewhere.