"With my doctors and everyone I spoke to, we're not going to put any set limitations on this," Miller said prior to the Bears' three-day mandatory minicamp.
"We're just going to take it as it goes. There has not been a definitive, 'you can never do this again.' That hasn't been talked about. It's to approach this as you are planning to get back to where I can be myself and play football and then when that time comes, some of that is out of my hands. So, I'm just going to do as much as I can to get that point and see what happens."
The Bears signed Miller to a one-year split contract Tuesday, and then promptly placed the veteran on the reserve/PUP list in order for Miller to continue rehabilitating his left leg.
Miller was rushed to University Medical Center New Orleans on Oct. 29 after he dislocated his left knee while making an over-the-shoulder catch in the end zone during Chicago's game against the Saints.
Miller's leg bent awkwardly on the play and he stayed down for several minutes until he was taken off the field on a cart.
Officials later ruled that Miller did not maintain possession of the ball, negating a potential touchdown catch.
Doctors performed emergency vascular surgery that night to repair a damaged artery in Miller's left leg that stemmed from the knee dislocation. Miller remained hospitalized in New Orleans for eight days before being transported back to Chicago in a medevac jet.
Miller underwent a total of nine surgeries, but he was spotted walking without a limp recently at the Bears' team facility.
"I'm feeling good," Miller said. "Knee's getting stronger, really daily. Putting a lot of work in here just continuing to work on strengthening that area, everything around it. That's kind of the big thing about this is it allows me to have that opportunity to continue to do that. So I feel good and continue to just get stronger, get healthier. Time will tell. Just put everything into it that I can and see where that takes me."
Miller smiled when a reporter asked him whether he has jogged since the injury.
"Is this on the record or off the record if I jogged?" Miller joked. "I'm not supposed to. A couple steps. I'm not ready to do that yet. I got steps that I got to take before I can do that. I imagine that I could but it's probably not the safest thing for me to do at this point."
Miller, who has battled injuries for much of his career, was one of Chicago's most consistent offensive performers in the John Fox era, catching 101 passes for 1,161 yards and 11 touchdowns over parts of three seasons with the Bears.
Miller also emerged as one of the Bears' most popular figures inside the team's locker room.
"That's my guy," Bears defensive lineman Akiem Hicks said of Miller. "Just seeing his road and the struggles that he's had to go through because of his injury, I am happy that I'm a part of an organization that will take care of its players. That's what it [the Bears' decision to sign Miller to a one-year deal] said to me that they're willing to make sure that we're all right and give us the opportunity to get better and just loyalty -- that's what I saw it as."
Miller will continue to receive treatment from Bears' doctors and trainers at Halas Hall, but he'll also sit in on tight end meetings.
The Bears signed free-agent tight end Trey Burton to be their primary pass-catching tight end in Matt Nagy's offense in the offseason -- Burton received a four-year deal that included $22 million in guaranteed money. Chicago also drafted tight end Adam Shaheen in the second round in 2017. Veteran Dion Sims is also expected to have a sizable role on offense in 2018. The Bears are scheduled to pay Sims $6 million for the upcoming season.
"My daily is, I'll be here, I'll rehab, I'll go to meetings, be a part of the football team as I had before, but obviously I'm just not able to play," Miller said. "Any way I can help any of the guys in our tight end room and really our football team, that's going to kind of be my role for the year."
"I don't think I've ever been mentally defeated -- ever. I feel good. I'm happy with where I'm at and with my recovery. I'm happy with the steps that we've made. Positivity has been one of my qualities that's helped get me through all this stuff. I'm in a good place right now."
Miller: 'I'm in a good place'
TE Zach Miller explains what it means to him to be with the Bears for the 2018 season.