The backup center has been out with the injury for most of training camp. Vandervelde also injured his back near the end of last season, but head coach Chip Kelly has said his current injury was not related to the previous one.
The Eagles drafted Vandervelde in the fifth round of the 2011 NFL draft. The Tampa Bay Buccaneers claimed him off waivers before the 2012 season began and placed him on their practice squad, but he returned to Philadelphia by the end of 2012.
Vandervelde has played in 15 games in his three-year career.
From the Philadelphia Inquirer:
"The sad thing is this is kind of how the NFL works," Molk said. "Your gain is someone else's [misfortune], which is terrible. It's the business."
Molk took 41 snaps in Friday's preseason loss to the Bears. He will continue to play with the second-team offense.
"I played well," Molk said. "A couple of little mental things, but overall, it was a really good game."
Undrafted rookie guard Josh Andrews could also take snaps at center.
- Sarah Barshop