LAKE FOREST, Ill. -- The Chicago Bears admit that rookie quarterback Mitchell Trubisky experienced certain mechanical issues that contributed to his poor numbers in last week's loss at Philadelphia.

"There were a couple things," Bears offensive coordinator Dowell Loggains said Wednesday. "He got caught bouncing a little bit and you know it was a tendency he had in college, and we talked to him a lot about keeping his shoulders and head still. He did get hoppy a little bit and there were some throws that were errant because of that and [that's] something we're going to keep working and grinding on that way."

Added Loggains: "There were some good things that he did. I thought that he improved in some ways. The thing that was most disappointing for me in the passing game was the uncontested, outside-the-number throws and a lot of that was -- to be completely honest -- a lot of it wasn't on him. When you have to run a 10-yard route and you run it at 8 yards, it's going to look bad and it's going to look like the ball sprayed and it's inaccurate, but he was going to the right spot with the ball."

Trubisky's performance in Week 12 is only part of the story. For a deeper look at his body of work, we asked ESPN analyst and former NFL safety Matt Bowen to review the film of Chicago's last three games against Green Bay, Detroit and Philadelphia.

Bowen discovered troubling themes but also reasons for encouragement when analyzing the third quarter of Trubisky's rookie season.

Pocket presence

Bowen: "What you're seeing in the pocket is classic young quarterback play. When Trubisky feels trouble he wants to hit the eject button and go lateral. But watch the top quarterbacks in the league, the first thing they are looking to do is step up in the pocket. When you hit the eject button and go outside, those routes aren't there anymore and they break down. Now you're throwing from a much more unstable platform because you're on the move and you're cutting the field in half when you do that as well. The backside receivers aren't in play anymore when you roll out.

"There's no doubt that when Trubisky can set his feet in the pocket and get his eyes down the field -- he can rip the ball. He can throw a deep out cut at 15-17 yards, throw a deep comeback, throw over the middle of the field and make a tight-window throw. But when his footwork falters a little bit -- that's when he gets into trouble.

"What I've noticed, especially on deep-ball throws down the field, like on a straight fly route and even some deep inside cuts, is that the ball sails on him. It's almost like a young pitcher that falls off the mound a little bit. He's falling away from his platform where he's throwing the football on some of the deep throws. That's causing accuracy issues and forcing him to miss down the field and forcing the ball to go high. That's really what you saw against Philly. They were just misses on the interceptions. And even the one that wasn't called an interception -- that was a miss."

'Not a lot of separation'

Bowen: "If I was an opposing defensive coordinator I'd play man coverage the whole game against this team -- if I had the cornerbacks. It allows you to challenge these receivers and force the rookie quarterback to make tight-window throws. There's not a lot of separation there, there's just not. If a defender is playing with outside leverage and funnels that wide receiver to the safety in the deep middle, that ball has to be on the upfield shoulder -- otherwise, it's a pick. It's just that simple because these wide receivers are not generating much separation.

"Trubisky still doesn't have a wide receiver that can go make a play for him when the ball isn't perfect. He doesn't have a guy that can catch the ball outside of their frame consistently, like a [Houston Texans receiver] DeAndre Hopkins. The narrative would be a little different if DeAndre Hopkins was playing with Trubisky. Anyone that's watched Hopkins, you saw him the other night working with Tom Savage, that ball from the quarterback to Hopkins doesn't have to be perfect because Hopkins is going to make the catch. In terms of having that top-tier No. 1 wide receiver, the Bears don't have that right now. That's going to impact some things. You have to be honest about that."

Fundamental flaws

Bowen: "You can make scheme excuses all you want but it doesn't matter if the technique and fundamentals aren't matching up. You can call the best route in the world and there might be a window there, but if the young quarterback's shoulders aren't square to the target and if he's falling off on his platform, it doesn't matter what you call.

"In the Detroit game, if Trubisky makes that throw to Benny Cunningham on the goal line Cunningham falls backwards and it's six points. He looked a little rushed and his footwork was off. He has to learn to calm down with it. If I was his coach, I'd turn that play on and say, 'Relax, it's just football.' You don't have to force the process, when a guy is open, just flip your hips and toss him the ball. In that situation he showed signs of his lack of experience and being in a moment where he played too fast."

Use Adam Shaheen

Bowen: "I would try and get Adam Shaheen on the field much more. Because he's a big-bodied guy that can create some leverage at the point of attack just because of his frame. If you're a safety, you're going up against a guy that's 6-foot-6. He's going to naturally create some leverage and some contact. Tight ends in the NFL are taught to push off and usually it's not called because it's an offensive league, and now you can run an inside break and you have more space to put the ball in compared to having to make a tight-window throw."

Brighter days ahead

Bowen: "The cool thing about this if you're [Bears GM] Ryan Pace, all this stuff can be corrected. You're not seeing talent deficiencies. This is fundamental football. Football 101 at the quarterback position is what these young quarterbacks have to go through in their first season. The game is much faster and the windows are much smaller. He's going through that growth process right now. That's why these reps are great for him. I know Bears fans want to see him win games, but these reps are vital to his development. He's got to play."