Trubisky, 26, returned to the starting lineup at Green Bay last week after a hip injury to Nick Foles rendered the 31-year-old inactive.
Trubisky passed for 242 yards and three touchdowns but committed three costly turnovers in Chicago's 41-25 loss to the Packers.
"After watching the mistakes, the main thing is taking care of the football," Trubisky said Wednesday. "It's easy to say, a little bit harder to do, especially going into it, you just have the mindset, 'I'm going to take care of the football, I'm not going to force things.'
"So, it's very obvious to say. You just have to go out there and do it."
The 2017 No. 2 pick traditionally plays his best football versus the Lions. In six career starts against Detroit, Trubisky has thrown for 1,601 yards, 14 touchdowns and four interceptions (106.0 quarterback rating) -- including four consecutive games with at least three touchdowns and a passer rating over 100.0. Trubisky threw for a career-high 355 passing yards against Detroit in 2018, and he led the Bears to an improbable fourth-quarter comeback victory at Ford Field in Week 1 of this season.
As for Foles, the veteran returned to practice on a limited basis Wednesday but is still recovering from the hip injury he suffered Nov. 16 against the Minnesota Vikings.
"I was watching Nick at practice ... trying to get a feel for him when he's in the pocket, you know; is he hesitant with stepping into his throws?" Nagy said. "What kind of velocity is coming off the ball? And I thought he did a pretty good job. I think for him, and I was asking him as we went, where he's at?
"I think he would be the first to tell you that, No. 1, it was good to get out there and do some of that. But at the same time, is he 100% where he needs to be? I would probably guess to venture that he would say no, he's not. So, part of these injuries, you know a lot of times some of that too can be the ability of understanding whether if you do a knee or a hip or your arm or whatever, is sometimes just the mental side of, OK, you just have to go through it a few times and get used to it and then once you do that, then the next day is better. And I think that's kind of where he's at right now."