(CNN) - Randy Scheunemann, a senior foreign policy adviser to John McCain, was fired from the Arizona senator's campaign last week for what one aide called "trashing" the campaign staff, three senior McCain advisers tell CNN.
One of the aides tells CNN that campaign manager Rick Davis fired Scheunemann after determining that he had been in direct contact with journalists spreading "disinformation" about campaign aides, including Nicolle Wallace and other officials. (Update: Davis denies the claim.)
"He was positioning himself with Palin at the expense of John McCain's campaign message," said one of the aides.
Senior campaign officials blame Schuenemann specifically for stories about the way Wallace and chief campaign strategist Steve Schmidt mishandled Palin's rollout - stories that the campaign says threw them off message in the critical final weeks of the campaign.
Another aide said McCain personally was "very disappointed by Randy," who worked for McCain for many years in the Senate.
Scheunemann became close with Palin during her debate prep process.