The strength of the Detroit Lions offense has quickly turned into a question mark.
Already without starting right guard Halapoulivaati Vaitai for at least the first month of the season, the Lions could be without Pro Bowl center Frank Ragnow for Sunday's season opener against the Philadelphia Eagles.
Ragnow did not practice Thursday because of the groin injury he suffered Wednesday, leaving the Lions to patch two-fifths of an offensive line that was supposed to be one of the best in the NFL this season.