With Game 3 of the World Series shifting to St. Louis, where National League rules mean the loss of the designated hitter, Red Sox manager John Farrell is opting to keep star David Ortiz in the lineup at first base, relegating regular starter Mike Napoli to the bench.

The move comes as no surprise, with the red-hot Ortiz having provided the bulk of Boston's offense in the first two games, in which he was 4-for-6 with two home runs, five RBIs and three runs scored.

Daniel Nava will get his first World Series start in left field Saturday in place of Jonny Gomes, the combination of Nava's left-handed bat against Game 3 Cardinals starter Joe Kelly and the bigger left field in Busch Stadium swaying Farrell's decision. The Red Sox had been 7-0 in the postseason in games started by Gomes until losing Game 2 by a 4-2 score Thursday night in Fenway Park. Gomes is 1 for his past 15 and batting .156 (5-for-32) overall in the postseason, although he was in the middle of several key rallies in earlier rounds.

"I've tried to stay in the game mentally with a couple of at-bats and take myself through an at-bat as if I was doing it," said Nava, who will start for the first time in 10 days. "Keep the routine the same. You have to be ready at any time."

Nava last started in Game 4 of the American League Championship Series against the Tigers, going 1-for-3 with a single. He has had just two at-bats since, both coming in the World Series as a pinch hitter. He doubled off Cardinals reliever Carlos Martinez in the eighth inning of Game 1 and came around to score, then struck out on a 99 mph fastball from Trevor Rosenthal to end Game 2.

David Ortiz will start at first base Saturday night for the Boston Red Sox in Game 3 of the World Series. Michael Ivins/Boston Red Sox/Getty Images

Meanwhile, Farrell is sticking with slumping shortstop Stephen Drew, who's batting just .095 (4-for-42) with 15 strikeouts in the postseason.

"He's such a steadying force for us up the middle and on the infield in general," Farrell said of Drew. "In games that we anticipate being played, defense is a premium. The first two games are a prime example. You give an opponent an extra out, you see what happens. It's happened on both sides, whether it's [Craig Breslow's] throw last night or in Game 1, where we were able to capitalize on some defensive inconsistencies on the other side."

Farrell also reiterated Friday that Clay Buchholz will be starting Game 4 on Sunday night.

After his formal media session Friday, Farrell disputed speculation that Buchholz cut short his throwing before Game 2 on Thursday because of shoulder discomfort. Buchholz played only a short game of catch before stopping.

"No, no, no," Farrell said when asked whether Buchholz had been unable to continue. "There are gradual steps he was building up. Today was much more intense, much greater volume. He's working in lockstep with our medical staff on this."

In his media session, Farrell said: "He went through his throwing program today. Got out to about 100 feet with increased intensity along the way. He's starting Sunday."

On Saturday, Farrell acknowledged there was "some conversation" about throwing left-hander and Game 1 winner Jon Lester three times against the Cardinals, given the uncertainty regarding Buchholz, but decided against it.

"History shows that's not been successful," Farrell said. "Even looking at the broader perspective, the last seven, eight weeks of the season he pitched on [the sixth day] the entire time. He pitched [on the fifth day] in Detroit, a little different stuff. It was noticeable.

"I recognize that we're in the World Series time of year, but I'd rather have Jon Lester at normal rest than three days of rest."

Information from ESPNBoston.com's Gordon Edes was used in this report.