The Phillies extended Chase Utley through the 2016 season and possibly beyond. While Utley's health has been questionable at best the last couple of season he has managed to stay on the field for most of the 2013 campaign.
Utley's Double Play mate at Shortstop, Jimmy Rollins, rarely gets injured and the two of them have spent a decade as the Phillies middle infield.
2011 Topps Heritage #72 Philly's Men Up the Middle
If the pair stay healthy they will be covering the Phillies Keystone through 2015. This doesn't make them Alan Trammel and Lou Whitaker, who played 1,918 games together, but it will make them one of the longest running DP combos in the games history.