Jason Kelce spent 13 seasons making life miserable for NFL defensive linemen. In London, the former Philadelphia Eagles center discovered that rugby forwards can deliver a similarly rough introduction to a new sport. Kelce, 38, made a surprise grassroots rugby union debut with Old Streetonians, playing approximately 30 minutes in a training match against local rivals Hackney RFC at Hackney Marshes. The retired Super Bowl champion was in the United Kingdom for the NFL London Games, where he was covering the Eagles' matchup against the Jacksonville Jaguars for ESPN, but found time to test himself in a sport that shares football's physical demands while requiring a different set of skills.