Theo Epstein and Terry Francona
Theo Epstein, left, has agreed to join the Cubs, according to a report. REUTERS

Boston Red Sox General Manager, Theo Epstein, resigned on Friday night to join the Chicago Cubs. The secret that was kept under wraps for so long was finally revealed, when the Red Sox and the Cubs held a joint conference to announce Epstein's resignation and appointment.

Epstein will join the Cubs on Tuesday, as President of the Cubs' baseball operations. The Red Sox are expected to name Ben Cherington, on the same day, as Epstein's successor.

However, the clubs have yet to come to an agreement over the compensation due to Epstein. Now that Epstein has officially left the Red Sox, Cherington and he are free to negotiate the compensation amount. If no deal is struck by Tuesday, Commissioner Bud Selig could step in as a mediator.

Epstein resigned with one year remaining on his contract. The Cubs, therefore, will need to compensate the Red Sox. The initial offer was one of cash. However, the Red Sox asked for Matt Garza or Stalin Castro, instead.

According to ESPN, at one point Boston proposed that the Cubs take pitcher John Lackey's contract; Lackey has three seasons remaining on an $82.5 million deal. He was 12-12 with a 6.41 ERA in 28 starts for the Red Sox in 2011.