QB Trent Dilfer, who helped the Ravens win a Super Bowl championship, is calling it quits after 13 seasons in the NFL. Dilfer told the Reno Press-Gazette on Wednesday that he is retiring and is planning a formal announcement in the next few days. Appearing at a golf tournament in Lake Tahoe, Dilfer said he suffered an Achilles tendon injury while on vacation this off-season, which just reinforced his decision to end his career. ?I was going to retire anyway,? Dilfer said. ?This just gives clarity to the situation.?