Bears coach Matt Eberflus said on Wednesday he plans to start Fields against the division-leading Lions.
"Our plan is to start him on Sunday," Eberflus said. "He continues to progress this week. Returning to practice today is going to be a big part of the evaluation."
Fields has thrown 11 touchdowns and 6 interceptions this season with a 61% completion rate. He has also rushed for one touchdown and 237 yards
A decision on Fields' fifth-year contract option is due next spring and the Bears can use this seven-week stretch to help decide if they want to go forward with Fields or possibly use one of their two first-round draft picks on a quarterback.
"I think seven weeks is enough time to show consistency and being the high performer that we expect him to be," Eberflus said. "I know he's had some good performances along this year, certainly the last few have been solid."
The Bears are coming off a 16-13 victory over the Carolina Panthers last Thursday.
Kickoff is set for noon in Detroit.
The Associated Press contributed to this report.