Philadelphia Eagles offensive tackle Lane Johnson is facing a 10-game suspension for violating the league's policy on performance-enhancing drugs, according to multiple media reports on Tuesday.

The reports included one on the National Football League's website.

Johnson was previously suspended four games for a doping violation in 2014.

Johnson is reportedly appealing the latest penalty, but at the moment the Eagles face the possibility of losing a key member of their offensive line for most of the season.

The 26-year-old Johnson, drafted in the first round (fourth overall) of the 2013 NFL Draft out of Oklahoma, signed a five-year, $56.2 million contract extension in the off season that made him the highest-paid right tackle in the NFL.

UPDATE - FOX Sports' Jay Glazer reports that Johnson "took an amino acid that was approved but tested positive for peptide. [Johnson is] fighting it as well as [the] company. You're responsible for what goes in your body but he insists it was approved. Waiting on B sample." - Matt Burke