One of the best guards in NFL history and a pretty sure bet for Canton, Marshal Yanda is retiring after 13 years with the Baltimore Ravens. He was still one of the league's top guards just this past year, helping the Ravens to set the NFL record for team rushing yards in a single season. Yanda made the Pro Bowl eight times and won a Super Bowl with the 2012 team. His likely replacement is 2019 fourth-round pick Ben Powers.