The Boston Red Sox and Toronto Blue Jays remained in negotiations to send manager John Farrell to Boston to be the team's manager, according to baseball sources.

"If they had this thing and it was that cut-and-dry easy for Toronto to pick somebody and the Red Sox were ready to give somebody up, this would have happened already," one source said. "I don't think it's that difficult of a decision."

The source guessed it would take a player or players of "substantial value" for the Jays to allow Farrell to go to a division rival, though the source did not have direct knowledge of the negotiations, which are taking place on multiple levels of each organization.

A baseball official familiar with the discussions told The Associated Press that the Red Sox have asked the Blue Jays for permission to talk with Farrell about the opening in Boston.

The Red Sox have formally interviewed four candidates -- Los Angeles Dodgers third-base coach Tim Wallach, New York Yankees bench coach Tony Pena, San Diego Padres special assistant Brad Ausmus and Baltimore Orioles third-base coach DeMarlo Hale -- to replace Bobby Valentine, but Farrell has been "at the top of their list" from the start, a team source told ESPNBoston.com earlier this month.