As first pointed out by Albert Breer of the Boston Globe, a story in the Denver Post today¬†revealed that a union source said New England’s Logan Mankins and San Diego’s Vincent Jackson along with Marcus McNeill were among unsigned restricted free agents who received letters indicating a cut in salary if they fail to sign their restricted free agent tenders.

The letter reportedly indicates an intent to cut¬†Mankins’ tender offer on June 15, the first day it is allowed by the league, to 110 percent of his 2009 salary.¬† That would lower his¬†salary number¬†to $1.54¬†in 2010, down¬†from the $3.268 million he was due to receive.

The team placed the 1st and 3rd round tender on Mankins earlier this year, which is the highest amount a player can receive.   According to Breer Mankins must sign his tender on or before June 14, or the tender is adjusted to the lower number.

Needless to say it appears the negotiations are beginning to get ugly, and we’ll likely hear more about this prior to the mandatory minicamp that is scheduled to begin on June 15th.