After playing a handful of snaps in the first half of Sunday's home game against the Cincinnati Bengals, Fields took over at quarterback in the third quarter for veteran Andy Dalton, who suffered a knee injury and didn't return.
Fields went 6-of-13 for 60 yards and an interception and rushed 10 times for 31 yards in the Bears' 20-17 victory.
"I don't think I'm pleased with how I played at all," Fields said. "I think there's a lot more in me that I have to show. That's going to come with time. I know it's not going to happen overnight, so I'm just going to keep grinding, and no matter what happens, I know I'm meant for this. I'm meant to be here. My path here has been crazy. When I was younger, I never thought I would be here in this position. I'm here for a reason. And I definitely think I can play better. I just think that this is the beginning. I'm definitely excited for the future and excited to get back to practice on Monday, Tuesday."
Dalton suffered the injury on a 14-yard scramble in the second quarter when he landed awkwardly on the Bears' sideline. Dalton immediately pointed to Fields to enter the game and headed to the blue injury tent to be examined.
He initially appeared to check out OK and reentered the game for a series before going back to the locker room prior to halftime. Dalton remained in uniform after halftime but did not have his helmet on while on the Bears' bench.
Bears coach Matt Nagy said he does not believe Dalton suffered a serious anterior cruciate ligament injury, but he did not want to speculate on Dalton's status as starting quarterback moving forward.
"I'm not going to get into that," Nagy said.
Nagy used Fields sparingly in last week's season opener versus the Los Angeles Rams. The first-round pick played five snaps and scored a rushing touchdown in the losing effort.
"Like I've said with Justin, he's probably further along than we thought at this point right now," Nagy said. "If that's the case [and Dalton has to miss time], we feel good about it with Justin. He has worked really, really hard to get to this point.
"We'll see where everything goes and where it's at, but Justin has done everything we've asked him to do and we feel good with him."