LAKE FOREST, Ill. -- Look for a heavy dose of Justin Fields Saturday.

Bears head coach Matt Nagy confirmed Thursday that Fields, currently Chicago's second-string quarterback, will see plenty of live action in the team's preseason debut against the Miami Dolphins. He might even play into the fourth quarter.

"For Justin, for sure [he'll play] past the halftime," Nagy said before the Bears and Dolphins held a joint practice.

"The mindset going into this is that he's going to get a lot of reps. Does that take him into the fourth quarter? Maybe ... the more reps we can get of him right now the better. It's only going to help him."

Fields has worked mainly with second-string skill position players since camp opened in late July.

However, Nagy left open the possibility of Fields, the 11th overall pick of the 2021 NFL draft, taking some snaps with members of Chicago's first-team offense on Saturday when he replaces veteran Andy Dalton, who is scheduled to play no more than one or two series versus Miami.

"That could happen," Nagy said. "I would like to see that happen. Again, it just depends what happens on that first drive with Andy and some of those guys. I would say there's a good possibility that could happen. There might be a time where we put him in and it just so happens that a guy like Darnell Mooney isn't in there but some of the others are. But there might be one or two plays where Mooney is in. It's a feel thing. This whole preseason is going to be a feel thing."

The Bears want Fields to play as much as possible the next two weeks, but to do so safely.

"The No. 1 goal is to get him as many reps as we can," Nagy said. "Then we as a staff have to be able to understand and feel the opponent we're playing, the matchups they have vs. us, where that's at. Because we want to be smart. We don't want to get in a situation where any these guys -- not just Justin -- are put at risk. That could be any position. But when you look at the quarterback spot, there is that balance.

"We've got to be able to evaluate. The only way you can evaluate is running stuff you want to run. It just can't be a certain scheme or play all the time. It's not fair to the offense. I feel like with our coaches we'll able to do that. We can scheme some things up and give him a chance. I just want him -- all those guys, same with Andy; I want him and Nick [Foles] and Justin to just go out and lead that offense. Don't worry about making mistakes. That's going to happen. Just play football. And if you just do that and you're the leader of that team and you score touchdowns, then we'll all be happy."