Theo Epstein officially joins Cubs

Theo Epstein has resigned from the Boston Red Sox in order to become the new president of baseball operations of the Chicago Cubs, the teams said in a joint news release Friday night.

The Red Sox and Cubs will both hold press conferences on Tuesday -- the Red Sox to announce their new general manager and the Cubs to introduce Epstein.

The teams said they would forego further comment until Tuesday out of respect for the World Series.