Naturally, manager John Farrell chose Ortiz, who, even at the age of 37, remains the most impactful hitter on the Red Sox.
"Like I said, he's starting tomorrow," said Farrell. "How we go forward through the remaining three games, we'll take a look at that day to day. But given the right-handed matchups, and even if you take away the matchups, David has got a long career that we all lean on. And we have the success that he's having in this postseason to take advantage of."
The big slugger figures to play a minimum of two games in St. Louis, if not all three.
"Whatever they need me for," said Ortiz. "We'll see how the situation goes, see how I feel."
The drawback is that every time Ortiz plays first base, Mike Napoli sits. After Ortiz, Napoli is Boston's best power hitter. Not only that, but Napoli has had some big hits in this postseason.
It's just that Ortiz is a different animal, particularly when the Cardinals are throwing all right-handed starters.
"Obviously, David's bat, at all costs, needs to be in the lineup, and I'm sure John will address that," said Game 3 starter Jake Peavy, who will essentially be taking Napoli's at-bats. "David is a game-changer. He's as clutch as anybody I can remember playing with or against. It just seems like he has a flair for the dramatic. When the situation is the biggest, he's at his best. And I'm glad he's on our team."
The Red Sox are also glad that Ortiz can hold his own defensively during the rare occasions he takes the field.
In 2004, Kevin Millar was the man who sat during the World Series games in St. Louis so that Ortiz could play. In 2007 it was Kevin Youkilis.
Ortiz made memorable plays on defense in both of those Fall Classics. In 2004 he zinged a perfect throw across the diamond to nail Jeff Suppan, who had gotten himself involved in a rundown. Three years later, in Boston's clinching Game 4 win at Colorado, he made a nice pick to help his team escape a rally.
"You only can play eight hitters in the National League, and I guess John wants me to be in the lineup tomorrow," said Ortiz. "I'm just getting ready for that."
Ortiz started six games at first during the regular season and handled all 37 of his chances cleanly.
"Hey, I mean, I'm down to do whatever my manager wants me to do," he said. "I'll just go out there -- wish me good luck."
It isn't an ideal situation for the Red Sox, who lose a key piece of their lineup in Napoli while the Cardinals go to battle with the same lineup they've used all year.
But those are the rules.
"Having always been in the American League, I favor [the DH]," said Farrell. "So, I guess, yeah, I would like to see the DH put in play. Obviously, it would take the traditional approach toward the National League-style game out of it."
When Peavy was with the Padres, he loved it when an AL opponent was disarmed by one key bat. These days, not so much.
"Yeah, if I were Commissioner, I'd certainly change it, where we could get Nap in there [on Saturday]," quipped Peavy. "I think that we certainly have a little bit of a disadvantage, just simply because of the way our roster is constructed as opposed to theirs. They're a National League ballclub, and they're going to play with their normal lineup tomorrow night, with the way they were built.
"Being an American League team, we're going to miss a huge middle-of-the-lineup bat tomorrow night. Our team was built with the DH in it, and it's unfortunate that that's got to happen."
This wasn't an issue for Napoli when he played for the Rangers in the 2011 World Series, as he was a catcher then.
But because of a hip condition -- diagnosed before he signed with the Red Sox -- Napoli didn't put on his gear all season, and that won't change in the Fall Classic.
"It is what it is," he said. "We're going to have to deal with it. Whoever's not playing that day is going to be prepared to come in late in the game and try to make something happen. Both teams have to have their pitchers hit. We both have good lineups out there."