In a spring in which Penn State could not afford injuries up front, the Nittany Lions will be without its most experienced offensive lineman for the foreseeable future. Multiple sources have indicated that senior guard Miles Dieffenbach will miss significant time with a serious knee injury suffered in practice this week.

The Fox Chapel, Pa., native was one of two returning starters for the Nittany Lions on the offensive line. He started all 12 games at left guard as a junior last season and 11 games as a redshirt sophomore in 2012.

He was an Academic All-Big Ten selection for the first time in 2013.

Dieffenbach's injury comes as a significant blow to the Nittany Lions' plans on the offensive line. Just he and left tackle Donovan Smith logged starts for Penn State last year among those currently on the roster. Dieffenbach slid over to right guard this spring in an effort to balance experience on the line.