Suspended players are eligible to participate in training camp and the preseason.
Johnson is due to make $495,000 this season. A suspension would cost him four game checks - a total of $116,470.
The Eagles face the Jaguars, Colts, Redskins, and 49ers in the first four games. Only Indianapolis ranked in the top 10 in sacks last season, and they will be missing star linebacker Robert Mathis, who was suspended the first four games for PED use.
Still, Johnson's suspension would hurt the Eagles' offense line, which benefited from remarkable stability in 2013-14. All five linemen started every game for the first time since 2006. They helped pave the way for running back LeSean McCoy's league-leading 1,607 rushing yards. The Eagles' first four games will be against the Jaguars, Colts, Redskins, and 49ers.
The Eagles selected Johnson with the No. 4 overall draft pick in 2013. It was their highest draft choice since Donovan McNabb at No. 2 in 1999.
Johnson was a starter from Day 1 for the Eagles, bookending a line with Jason Peters at left tackle. He played 1,103 snaps - all but one of the Eagles' offensive plays last season. The Eagles averaged 4.55 yards per carry when they ran behind the right tackle, and 5.29 yards per carry when they ran around the right edge.
Johnson's backup is Allen Barbre, who was was suspended for the first four games of the 2012 season with Seattle before being released by the Seahawks once his suspension was up. The Eagles gave Barbre a three-year contract extension last month.
Dennis Kelly started 10 games in 2012, but he did not get into a game last season. Other alternatives include second-year lineman Matt Tobin, and Michael Bamiro, who spent all of last season on the practice squad.
During the offseason, the Eagles signed Andrew Gardner, who has played in eight games over four seasons with four teams, and undrafted tackle Kevin Graf.
Johnson has added weight throughout his career. He weighed about 200 pounds as a high school quarterback in Groveton, Texas. The scale read 255 pounds when Oklahoma recruited Johnson out of Kilgore College, and Johnson labored to keep his weight over 270 pounds with the Sooners. When Oklahoma coach Bob Stoops asked his strength coach what it would take to get Johnson to put on enough pounds to move from defensive tackle to offensive tackle, the coach answered, "A cheeseburger and a week."
The Eagles have experienced suspensions before. Cornerback Joselio Hanson missed four games in 2009 after violating the league's drug policy. Defensive back Matt Stevens was docked four games in 1997. Former first-round pick Bernard Williams dealt with marijuana suspensions, including an indefinite one, in 1995. Offensive lineman Ron Solt sat out four games in 1989.