"We're pretty far apart," Frank Bauer told the Boston Herald. "Let's leave it at that."
Mankins has skipped the Patriots' voluntary workouts this offseason, and Bauer said "no comment" when asked if the restricted free agent would miss a mandatory minicamp next month if he doesn't have a deal.
Mankins has until June 15 -- the day the minicamp starts -- to sign his one-year, $3.268 million tender offer. Patriots owner Robert Kraft said he hopes Mankins "will be with us for the long term."
It isn't known what Mankins is seeking in a new contract, but New Orleans Saints guard Jahri Evans recently signed a seven-year, $57 million deal. Mankins, 28, is two years older than Evans and has made one more Pro Bowl.
Mankins was a first-round draft pick (32nd overall) by New England in 2005. He has started in every game during his NFL career.