Mitchell Trubisky feels prepared to take on backup duties.

LAKE FOREST, Ill. (AP) Regardless of rookie Mitchell Trubisky's inexperience, Chicago Bears coach John Fox has full confidence his backup quarterback can play effectively for starter Mike Glennon if needed Sunday in the opener against the Atlanta Falcons.

The ''it factor,'' is one good reason.

Fox said Friday he saw leadership abilities in Trubisky after only a brief time, leading to a decision this week to designate the former North Carolina star as the backup to Glennon ahead of veteran Mark Sanchez.

''So I think very early on for us as coaches, I think we saw the tenacity with which he goes about it and the maturity with which he prepares,'' Fox said. ''And then there's just a kind of an `it factor,' in how you relate to people around you and how people feed off you, that I think was pretty evident early, too.''

The Bears have touted their depth as being dramatically improved, and this goes for the quarterback position.

''We joke about next man up, but I'd feel pretty confident about Mitch playing in any game,'' Fox said. ''You know, I want everybody to stay healthy though, let's make that fact very clear.''

Trubisky wasn't downplaying his ability to lead, or even the `it factor' Fox says he has.

''Yeah, I kind of feel that,'' Trubisky said. ''I guess it's just how you carry yourself and how you respect your teammates, and in return they respect you as well.

''So I just go out there and give everything I got. I think my teammates know that and I think they know that I have a lot of love for them and I love playing this game.''

Fox earlier this week said Trubisky earned the promotion to backup rather than serving as a third-string developmental project like the team originally announced.

''I feel like I did,'' Trubisky said. ''I worked really hard. I played pretty well in the preseason games and just continue to work and show that I'm prepared for this step in my career right now.''

Being a backup isn't entirely an unknown feeling for Trubisky, the second pick in this year's draft. He did it at North Carolina before becoming starter.

''I think you can take from that experience, preparing as a starter at all times and then just being ready to come off the bench at any given moment and be ready to play and help your team,'' Trubisky said.

Trubisky credited part of his success to Sanchez.

''On and off the field, in the film room, (he's) always making me better, constantly in my ear and being aware of the situation and totally honed into the game and to the task at hand,'' Trubisky said.

Trubisky spent the week getting very few play repetitions in practice with starters, and sometimes ran the scout team.

When he arrived in Chicago, Trubisky felt like a bit of an outsider, as any new player might. That's no longer the case.

''Yeah, it's probably 180 (degrees),'' Trubisky said. ''You just come in here as a stranger and now you feel like one of the guys and you're really a part of this team that's slowly becoming a close family.''

It's been this way with Chicago fans, as well. All the No. 10 jerseys being worn at Soldier Field in preseason made this evident.

''Yeah, I've seen them,'' Trubisky said. ''It feels pretty cool.''

NOTES

Guard Kyle Long (ankle) and linebacker Pernell McPhee (knee) go into Sunday's game as questionable on the injury report after practicing Friday on a limited basis. ... Wide receiver Markus Wheaton (finger) is questionable, but downplayed his chances of playing Sunday because he has just begun to catch passes after surgery on his pinky finger. ... Cornerback Prince Amukamara (ankle) missed practice all week and is doubtful after suffering an injury early in the third preseason game. If unable to play, Amukamara will be replaced by Kyle Fuller. ... Running back Ka'Deem Carey and quarterback Connor Shaw were waived from injured reserve.

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