"Surgery is very unlikely," Francona said. "But he will be placed on the disabled list. He'll be placed in a splint [or] soft cast. We'll certainly have more information [Tuesday]. That's kind of where we are tonight."
The Boston Herald reported that Ortiz will miss at least a month. However, the Red Sox will wait until at least Tuesday before giving a more specific time-table.
"I wouldn't speculate, because I don't know," Francona said. "I haven't been there. All of us want to get a chance to talk to David, and to the doctors. We'll map this out to the best of their ability. We really don't know more now. I can't tell you more."
The injury occurred in top of the ninth inning of Saturday's game, when Ortiz took a full swing and then heard a pop. He immediately came out of the game.
After undergoing treatment from the training staff on Sunday, Ortiz flew to Boston on Monday morning. He was examined by Red Sox medical director Dr. Thomas Gill.
Since becoming an everyday player in June 2003, Ortiz has been one of the most feared sluggers in baseball. After a slow start in 2008, Ortiz had gotten hot recently. He is hitting .252 with 13 homers and 43 RBIs.
"We've got to keep playing the same way we're playing until he gets back," said Red Sox left fielder Manny Ramirez. "He's a big part of the team. We need him. What can you do? You don't plan to get hurt. When things happen, you have to be patient and let's keep playing the way we're playing and wait for him."
During Ortiz's absence, first baseman Sean Casey and center fielder Coco Crisp both figure to see more action. The Red Sox are also likely to enlist some help from the Minor Leagues, with left-handed-hitting outfielder Brandon Moss seemingly a logical candidate to be called up.
"We have good hitters," Francona said. "Casey is one of them. Casey could see some at-bats. We could have Manny sometimes DH and have an outfield that runs all over the place."
As much as Casey looks forward to seeing some more at-bats, he never wanted it to come at the expense of one the best hitters in baseball.
"We'll all try to bide time while David is gone and try to hold down the fort until he gets back," Casey said. "You can't replace a guy like David Ortiz. He means so much to our club and to the game of baseball. What he brings every night to the Boston Red Sox is irreplaceable. We're going to have to do without him for a few weeks, obviously."
It will be particularly strange for Ramirez not to have Ortiz by his side for the near future. The two sluggers have been bashing opposing pitching staffs in tandem for the last five years.
"Let's wait for him and pray that he gets better soon and move on," said Ramirez. "I don't know. I'm so used to me and him in the same lineup. I just have to wait and see."