Jason Fox isn’t wasting any time in his bid to win a starting tackle job with the Lions. Fox, one of the Lions’ two restricted free agents, will sign his one-year tender offer today and take part in the team’s first day of off-season workouts. A fourth-round pick out of Miami in 2010, Fox is expected to contend for one of two vacant tackle jobs after the Lions let Gosder Cherilus walk in free agency and Jeff Backus retired. Fox has played sparingly in his three seasons as a Lion, filling in at right tackle for one half of one game as a rookie. He missed part of his first two seasons with foot and knee injuries, and was the Lions’ No. 4 offensive tackle for most of last year. With Cherilus and Backus gone, the Lions are debating how best to fill out their offensive line. Fox can play either tackle position, Corey Hilliard and last year's first-round pick Riley Reiff also are candidates to start at tackle, and the Lions could draft an offensive lineman with the No. 5 overall pick. Reiff also can play right guard, which is open after Stephen Peterman was released in February. The Lions made qualifying offers to both Fox and defensive end Willie Young before the start of free agency last month. Young, who the Lions hope will help fill the loss of Cliff Avril, also is expected to sign his tender.