FILE - In this Aug. 7, 2013, file photo, New England Patriots' Tim Tebow walks onto the field during a joint workout with the Philadelphia Eagles at NFL football training camp in Philadelphia. Tebow says he is not done with the NFL even though helping ESPN launch the SEC Network was too good an opportunity to pass up. Tebow stresses he will keep training in hopes of returning to the NFL as a quarterback. (AP Photo/Matt Rourke, File)