From the moment Bill Parcells took over the Miami Dolphins and began drawing up plans for his offensive line, the interior three blockers have been a volatile mix.
The Dolphins are entering their third season under Parcells and head coach Tony Sparano, whose professional foundation was built on the offensive line.
In a short time, the Dolphins are on their second O-line assistant coach, perhaps their third different starting center (Samson Satele to Jake Grove to Joe Berger) and maybe their sixth and seventh different starting guards.
Miami's interior line became even more unstable in the past few days.
Nate Garner, who started four games at left guard and four games at right guard last year, underwent foot surgery that reportedly will sideline him at least eight weeks. He had surgery on the same foot over the offseason.
Third-round draft choice John Jerry, the starter at right guard in Saturday night's preseason opener, also is hurt. He suffered a knee injury at the end of Monday's practice and was unable to participate Tuesday.
Richie Incognito and Donald Thomas are battling for the left guard spot, although Thomas can be switched to the right side if Jerry's injury becomes an issue. Thomas has started at right guard the past two opening days, but he's injury-prone. Cory Procter practiced at right guard Tuesday.