This summer, Glennon makes his preseason debut against the Denver Broncos as Chicago's unquestioned No. 1 quarterback.
"It'll be different going out there right away," Glennon said on Monday. "When you're the backup in the preseason it's kind of a weird feel because you know you're going to get in and you're not exactly sure when. So now it's mentally going into the game, you know you're going to be in there right away. I'm looking forward to that. It'll be a little bit different."
Glennon hopes his first live action at Soldier Field in a Bears' uniform goes as well as the first preseason game he played in 2013.
"We played the Ravens and they were just coming off their Super Bowl win," Glennon said. "First play, I was backed up on the 1-yard line going out, and I dropped back and my first read wasn't there and I thought I was going to get sacked in the end zone. I remember flashing like, 'Oh my God.' And there was a guy open and it went for like 60, 70 yards. So it was kind of a good way to settle in and be going. It's definitely a different experience going from college to the pros that first time."
Typically, John Fox plays the starting quarterback a series or two before the backup takes over. Veteran Mark Sanchez is likely the first quarterback off the bench, but Fox confirmed on Monday that rookie second overall pick Mitchell Trubisky is expected to play versus the Broncos.
"I think it will be fair to say he'll get some reps in the Denver game," Fox said.
Trubisky appears to have settled in over the last week. The rookie has nice touch on his deep passes and moves exceptionally well to his right when flushed out of the pocket. There's still no quarterback controversy in Chicago, but Trubisky has definitely shown incremental improvements since the Bears began practicing in Bourbonnais on July 27.
"When he first got here, you could see a little bit of timidness," Bears tight end Zach Miller said. "But then you can start to see how he talks in that huddle, how he spits the plays out, different reads now, going from here to here to here and doing it in a progression. He's doing quite well and the future's bright for him as well. He'll just keep on working and keep on getting better."
Glennon offered Trubisky some advice in advance of the exhibition opener.
"I think just the biggest thing is, you belong in this league," Glennon said. "You don't really know until you do it, and then once you do it you finally realize it. So just go out there, play like you have your whole life and you'll be fine."