Injured Lions QB Matthew Stafford stands to the side while other QBs participate in drills

Injured Lions QB Stafford at practice, not drills

ALLEN PARK, Mich. — Detroit Lions quarterback Matthew Stafford is back at practice but his return to the field remains unclear.

Stafford stood to the side in his jersey and a baseball cap while Detroit’s other two quarterbacks participated in drills Wednesday during the portion of practice open to reporters.

Stafford was knocked out of the season opener when Chicago’s Julius Peppers sacked him Sunday, putting him on the sideline with a banged-up right shoulder — his third injury in two seasons.

Coach Jim Schwartz said earlier this week he didn’t think Stafford would need surgery, but he didn’t put a timetable on a return.

The Lions will host Philadelphia in their home opener Sunday.