Receiver Allen Robinson II was not targeted while playing very little during the preseason. But coach Matt Nagy isn't worried about the prized free-agent acquisition making an impact once the regular season begins Sunday night in Green Bay.

"He hasn't played a whole lot, so those catches don't concern me at all," Nagy said. "What I've seen in practice, I know that he's going to be able to go out there and play fast. He knows what he's doing. I have 100 percent trust in him as a player. I know that Mitchell [Trubisky] does too. Now they've got to go out and do it under the lights."

Robinson signed with the Bears in March after spending his first four NFL seasons with the Jaguars. Fully recovered from a torn ACL he sustained in Jacksonville's season opener last year, the 6-3, 211-pounder is trying to revert to his pre-injury form. Robinson was voted to the Pro Bowl in 2015, recording 80 receptions for 1,400 yards and 14 touchdowns. He followed with 73 catches for 883 yards and six TDs in 2016.

"I think the biggest thing that you'll see for him is going to be the contested catches," Nagy said. "When the DBs are clamping on your back and you've got to make the contested catch, that's the one in practice you might not see as much, but him being a veteran, I think he'll be OK with that."

Miller time: Another receiver who bears watching is rookie second-round pick Anthony Miller, who stood out throughout training camp and the preseason.

"He's a kid that has extreme talent, that we're trying to keep an eye on in regards to the mental side of it," Nagy said. "We knew physical. He was flashing in practice early on and he has that confidence; we told you when we drafted him that he has that confidence. That showed up.

"But he had to control it to where it's not a cockiness. He made some plays that jumped out to us. We understood how he was going to start fitting into this offense, to what role, and what we did was kind of pull back and say, 'He fits physically, but where does he fit mentally?' Over the past few weeks we've been trying to test that out and he fell into that range for us. In the preseason games, we felt he was OK with where he's at. Now we'll just figure out where's the best spot for him in this upcoming game."

Building chemistry: Five of Trubisky's 11 completed passes in the preseason were caught by tight end Trey Burton, including a 7-yard touchdown Aug. 18 in Denver.

The two have developed a rapport, primarily by working together in practice.

"The reps we weren't getting in games, we were throwing the day of the game and many days before that," Trubisky said. "Just all the timing, the repetition and the routes we ran, and then just building that chemistry on and off the field with Trey and with all those guys.

"I feel really good with where we're at chemistry-wise between me, the tight ends, the receivers, the running backs and all that. Just with all the reps that we've had in practice, but it has to translate to the games. Everybody knows it's different from games to practice, practice to games. We've just got to go out there, everyone do their jobs and hopefully the timing and the chemistry that we build pays off in the game."