The Detroit Lions committed to keeping offensive tackle Jason Fox on Monday, tendering the restricted free agent. The team also tendered three of its four exclusive rights free agents. MLive has confirmed the Lions extended offers to safety Ricardo Silva and fullback Shaun Chapas, and the Detroit Free Press is reporting wide receiver Kris Durham will also be brought back. It is assumed, after a breakout campaign in 2012, running back Joique Bell will also be tendered by the franchise prior to Tuesday's 4 p.m. deadline. An exclusive rights free agent is a player with fewer than three accrued seasons. The tender is a one-year contract at the veteran's minimum. The salary is not guaranteed. Since only the top 51 salaries count against a team's salary cap during the offseason, the impact of these four signings will be minimal.