Francona, who turns 46 on April 22, said all morning he was not feeling well, according to general manager Theo Epstein. Before Boston's game against the Yankees, Francona was taken by ambulance to New York Weill-Cornell Medical Center in Manhattan, where he has relationships with several doctors.

Epstein said the Yankees made all of their staff available to Francona. Red Sox team doctor Thomas Gil was monitoring Francona's condition by phone from Boston, and team trainer Jim Rowe accompanied the manager to the hospital.

Bench coach Brad Mills was to fill in for Francona in Wednesday's game against New York. Francona was not expected back for the game.

Epstein informed the team about Francona after the second Red Sox bus arrived at the stadium around 10:30 a.m.

"It was scary because you're talking about real-life stuff, you're not talking about wins and losses," Boston first baseman Kevin Millar said.