McDaniel said Williams' absence is not excused although the two sides have been in communication; Williams was not at the team's OTA's practices last month either, although those are voluntary.
The former Dallas Cowboy signed a two-year deal with Miami last offseason and moved from left guard to center, where he started all 17 games. The 26-year-old is owed $7 million in the final year of his deal with the Dolphins.
Williams was Miami's best offensive lineman behind Terron Armstead last season but does not have a clear-cut successor. Free agent signing Dan Feeney could possibly fill the role as the team works things out with Williams.