The Detroit Lions have started three different combinations on the offensive line in their first four games of the season, and they could be looking at another grouping Sunday.
Center Frank Ragnow did not take part in position drills Thursday, one day after he landed on the injury report with a groin injury.
"Just something that popped up (Wednesday)," Lions coach Matt Patricia said.
Ragnow has been one of the Lions' most durable linemen during his two-plus seasons in Detroit. He missed one snap as a rookie due to an equipment malfunction, sat out one game last season with a brain injury and has played every offensive snap through four games this year.