Theo Epstein and the Chicago Cubs have agreed to a massive five-year deal for him to join the team, sources told ESPN The Magazine's Buster Olney Wednesday.
Original reports have put the total compensation at between $15 million and $20 million, and the deal includes the Cubs picking up the conclusion bonus in Epstein's Red Sox deal, sources said.
Epstein has been to Chicago on two separate occasions to meet with Cubs officials, sources said. He was Red Sox general manager for nine seasons and had one year remaining on his current deal in Boston.
According to sources, Major League Baseball expressed great concern over the compensation package because they do not want this deal to affect how other teams compete in the market for front-office personnel.
A source with knowledge of the talks told ESPN's Karl Ravech Tuesday that the compensation would involve prospects and/or cash, but no major league players would be part of the deal, following traditional precedent.
WEEI, which first reported an agreement between Epstein and the Cubs, said that a title has not yet been agreed upon, but it has been assumed that he will get a higher title than what he had on the Red Sox, executive vice president/general manager.
Since the possibility of Epstein going to the Cubs first surfaced in August, Red Sox ownership has downplayed the notion because Epstein is under contract with the Red Sox through 2012. But at no point have Red Sox owners John Henry or Tom Werner ever squashed the talk completely, nor has Epstein definitively ruled out the move.
Neither the Cubs nor Red Sox has formally acknowledged that the Red Sox granted permission to the Cubs to interview Epstein, but an industry source said Tuesday that Cubs owner Tom Ricketts spoke with Epstein last week and that Epstein met with Cubs president Crane Kenney in Chicago last weekend.
Sources indicated last week that the Red Sox have had informal conversations about changes in the event that Epstein did leave for the Cubs -- and at the top of their hierarchy, there have been some discussions about the identity of the next manager without Epstein.
The Red Sox also have had informal conversations about candidates other than assistant GM Ben Cherington to replace Epstein. But Cherington appears to be the heir apparent.
Epstein likely will be restricted, in an agreement between the teams, from bringing any Boston employees with him without approval from the Red Sox, according to an American League source.
Executives with the Red Sox either declined comment or did not respond to requests for a response. Epstein did not respond to a request for comment, although there were indications Tuesday night that the Red Sox were hoping that Epstein might yet change his mind.
But one Red Sox official said Tuesday that Epstein's departure would not come as a surprise.
"It wouldn't shock me,'' the official said, "but until it happens I won't believe it.''
The last two Red Sox forays into hiring a general manager have taken last-second twists. In 2002, the Red Sox struck an agreement with Oakland's Billy Beane to become GM, only to have Beane call Henry two days later to inform him that he had changed his mind. That opened the way to Epstein's hiring.
Then in 2005, Epstein left the club in a dispute with CEO Larry Lucchino, and the team subsequently hired Cherington and Jed Hoyer as co-general managers. Epstein's departure was short-lived; he was back as GM within three months, with Hoyer later leaving to become general manager of the San Diego Padres.
Cherington's first order of business, if promoted, would be to hire a manager to replace Terry Francona, who left after eight seasons in the job. In Chicago, Epstein would be replacing Jim Hendry, who was let go in July after becoming Cubs GM in 2002, the same year Epstein began with the Red Sox.
The Cubs have manager Mike Quade under contract for one more year.
ESPN The Magazine's Buster Olney and ESPNBoston.com's Gordon Edes contributed to this report.