ALLEN PARK, MI(WKZO) - Cliff Avril has signed his one-year restricted free agent offer with the Lions.  The defensive end can now practice with the team.  The signing was considered a formality.  Just 25, he will be one of the top free agents next year, if he’s allowed to test the open market.  Avril had a career-high 8 1/2 sacks despite missing three games with injuries last season.  Avril is a member of what many experts consider to be the strongest part of the Lions’ team- the defensive line.