Fields practiced in full Thursday and Friday after being listed as limited Wednesday. He did not carry an injury designation on the final report of the week and is active for Sunday's game.
The quarterback was considered "day-to-day" by the Bears earlier in the week but gained more mobility and strength, according to coach Matt Eberflus, as the days wore on, which led to his status being upgraded Thursday.
Fields fell on his left shoulder after he was tackled by on a first-down run nearing the end of Chicago's 27-24 loss at Atlanta. He classified his injury as a separated shoulder with partially torn ligaments, calling it "basically an AC joint," and was limited throughout practice last week.
Asked whether the Bears feel there is any risk of further injury, Eberflus pointed to confidence the team has in the quarterback's improved mobility and strength.
"Right now he feels, and we feel, that the mobility and strength is there for him to protect himself and he feels like he's 100 percent, ready to go," the coach said.
Fields returns to a team looking to avoid its sixth straight loss and earn its first win since Oct. 24 at New England. The Bears are hosting the second meeting with their division rival after losing in Green Bay back in Week 2. Quarterback Aaron Rodgers will start against Chicago despite sustaining a rib injury against Philadelphia.
On Thursday, Bears wide receiver Velus Jones Jr. noted the excitement Fields' return provided the offense. Receiving positive injury news with the Bears quarterback after wide receiver Darnell Mooney and safety Eddie Jackson exited the Jets game with season-ending injuries was celebrated team-wide.
"It's great," Eberflus said. "Obviously when you get your starting quarterback back, a guy that's electric like that and makes a lot of plays for our football team, it's obviously a big boost in the arm to the whole football team. Guys are excited out there, not only the offensive guys but the defense and special teams. Everybody's excited that he's out there moving around and being himself. Certainly missed him last week."
Nathan Peterman will serve as Fields' backup after Trevor Siemian elected to have season-ending surgery on his oblique muscle, according to Eberflus. Siemian sustained the injury during pregame warmups at MetLife Stadium but was able to play through it. Eberflus did not know whether Siemian re-injured his oblique while diving for a first down against the Jets.
"Super smart, great teammate, always encouraging to Justin and everybody in the room," Eberflus said of Siemian. "He was a joy to be around and is an excellent, excellent pro."
Peterman will be elevated to the active roster off the practice squad for the second straight week. Tim Boyle, who signed with Chicago on Wednesday, is inactive Sunday.
This is not the first significant injury Fields has played through during his career. During his final season at Ohio State, Fields received a crushing blow in the first half of the Sugar Bowl and played through an injury to his ribs and hip to lead the Buckeyes past Clemson to the national championship round.
Eberflus noted the importance Fields' resilience has on the rest of the team and the type of players the Bears hope to construct their roster with moving forward.
"It shows the kind of guys that we want," he said. "We want guys that are tough, that are physical and again, he's been medically cleared to play and he's 100 percent. Going forward, we'll see where it goes. Hopefully, it keeps trending that way and go from there."