LAKE FOREST, Ill. -- The changing of the guard at quarterback in Chicago is now complete.

Chicago Bears head coach Matt Nagy changed course Wednesday and announced that rookie Justin Fields is the team's starting quarterback moving forward, regardless of veteran Andy Dalton's (knee) health status.

The Bears (2-2) travel to Las Vegas to take on the Raiders (3-1) on Sunday.

For weeks, Nagy insisted that Dalton remained the Bears' starter when healthy, but Fields' performance in last week's 24-14 victory over the Detroit Lions forced the organization to scrap its original quarterback plan.

"After this past weekend with Justin and the growth that we saw, the discussions that we had was to be able to go in this direction," Nagy said.

Fields completed 11 of 17 passes for 209 yards and one interception versus the Lions, but he had five passes that went for 20-plus yards as Chicago's offense bounced back from a historically bad performance in Cleveland the week before.

"It is a big decision, but we feel very good about it and are looking forward to it," Nagy said.

On the year, Fields is 25 of 52 (48.1%) for 347 yards, two interceptions and 55 rushing yards on 17 attempts and one touchdown.

Dalton started the first two games for Chicago but suffered a bone bruise in his left knee in the first half of Week 2's win over the Cincinnati Bengals. Dalton has been inactive the past two games.

"The No. 1 thing that I understood as a head coach and that we all understood as an organization is knowing that when you make a trade up to go get a guy to develop and be the franchise quarterback, you always know that there's going to be that want to get him in there ASAP," Nagy said.

"At the same point in time, again, we had our plan with Andy and developing Justin. And so, I think that for me, I knew it came with the territory, and all we wanted to do was do everything we can to do what's best for this team. And again, I'd be lying to you if I sat here and told you it wasn't really hard to have that discussion with Andy. Those are not easy discussions because there's the human side of it, and I don't care who you are, if you've got a good heart, that stuff hurts."

Nagy informed the quarterbacks of the switch on Tuesday.

"It was definitely good news to hear," said Fields, whom the Bears traded up nine spots to draft 11th overall in the spring.

"I would say I was a little bit surprised, but I mean, not really crazy surprised. But definitely a little bit of surprise. I feel like he was pretty straightforward with me and Andy. And I think my teammates believe in me, so just grateful for the opportunity and just trying to get ready to work."

The expectation is that Dalton's knee will be healed enough for him to be the No. 2 quarterback on Sunday in Las Vegas.

"One thing that Andy has earned from me and our coaches is a hell of a lot of respect, because that guy is a freaking stud," Nagy said. "I'm so glad he is on our team and I appreciate the way he understood it and the way he handled it, but he also cares immensely about this team and I appreciate that."