Schwartz said regular starter Matthew Stafford is doing well in his rehabilitation for his injured shoulder, but the coach and player haven't said what the timetable is for his return. A league source told NFL Network insider Jason La Canfora that the team expects Stafford to miss four to six weeks.
Stafford, the No. 1 overall pick in the 2009 NFL draft, was knocked out of the Sept. 12 season opener when Chicago's Julius Peppers sacked him -- putting him on the sideline with his third injury in two seasons. Stafford missed six games last year with an injured left shoulder and right knee.
Hill has completed 53 percent of his passes for 423 yards with two touchdowns and three interceptions in two games this season, both losses.
The Associated Press contributed to this report.