NEW YORK -- With Alex Rodriguez shelved by his strained left calf, Eduardo Nunez earned his first Major League start on Saturday.

Called up from Triple-A Scranton/Wilkes-Barre on Thursday, Nunez has been a defensive replacement each of the past two days, fouling out in his lone at-bat.

Nunez was promoted to the big club for just this reason, providing extra infield depth behind Ramiro Pena, with Rodriguez's status uncertain for the next several days.

"He finds a way to put the bat on the ball," manager Joe Girardi said of Nunez. "We believe that he can be an exciting player. They started playing him at second base and third base in Triple-A so that we would have some options. We believe this kid is gifted athletically and could be a real plus for us."

Nunez had spent the entire season at Triple-A Scranton/Wilkes-Barre, compiling a .289 average with four homers and 50 RBIs in 118 games. The 23-year-old is a career .274 hitter in six Minor League seasons, although he has brought that average up over the past two seasons.

Although Nunez has been a shortstop for the large majority of his professional career, he did play 11 games at third this season in Triple-A. He got his first big league crack at the hot corner on Friday night, coming in as a defensive replacement for one inning.

"He's always been a kid with big tools, and sometimes you've got to wait on the tools," general manager Brian Cashman said on Thursday. "The last two years, he's kind of put it all together. ... He's earned the right to be in the big leagues."

Calf strain forces A-Rod to disabled list

NEW YORK -- The Yankees placed Alex Rodriguez on the disabled list on Saturday, one day after he aggravated his strained left calf against the Mariners.

"We're going to play it safe," manager Joe Girardi said. "We don't feel he's any worse than he was before, but we're just going to play it extremely safe here and know that we'll have a player in 15 days."

Rodriguez initially injured his calf on Monday, leaving a game against the Tigers after four innings. His return to the lineup on Friday night as the designated hitter lasted all of one at-bat. With his only swing of the night, Rodriguez grounded out to third and jogged very gingerly out of the box. He was lifted for a pinch-hitter two innings later.

Girardi had said before the game that although he didn't expect Rodriguez to play this weekend or even in the following series in Toronto, he did not think the disabled list was likely. That thought changed sometime after Rodriguez arrived at the ballpark.

"[General manager Brian Cashman] talked to the doctors and the trainers, and we just felt it was probably in the best interest to put him on the DL," Girardi said.

Rodriguez and the Yankees maintain that the most recent instance of his injury is no worse than the first one earlier in the week. The third baseman said on Friday that, since he's never had a calf injury before, he's had trouble determining what exactly he can play through.

With Rodriguez out, the Yankees will turn to youngsters Ramiro Pena and Eduardo Nunez to fill his considerable shoes. Pena is batting .197 on the season, but he does have 16 RBIs on just 23 hits. The Yankees are 22-8 in games he starts.

Nunez, meanwhile, made his first Major League start on Saturday, driving in the go-ahead run in the seventh with his first career hit.

"Those guys are what we have right now, and we'll continue to evaluate on an everyday basis," Girardi said. "These guys have done a pretty good job filling in."

Indeed, Saturday's win improved the Yankees' record to a remarkable 11-0 in games in which Rodriguez does not appear. New York was just 21-17 in such games a season ago.

"You can't help but miss a guy like Alex, but we're going to do our best," Mark Teixeira said. "We all have to continue to play well and pick each other up."

Right-handed pitcher Ivan Nova will be called up to replace Rodriguez on the roster. Nova will make his first career start on Monday in Toronto.

Nova to get callup, start for Yanks on Monday

NEW YORK -- The Yankees announced on Saturday that they will call up right-handed pitcher Ivan Nova to make his first Major League start on Monday in Toronto. Nova is filling the roster spot of Alex Rodriguez, who was placed on the disabled list.

Nova, 23, has been tremendous this season for Triple-A Scranton/Wilkes-Barre, pitching to a 12-3 record with a 2.86 ERA in 23 starts. He tossed three scoreless innings for the Yankees earlier this season, all in relief.

Nova will make the start on Monday with everyone else getting an extra day off. Manager Joe Girardi did not say whether the team would skip anyone's turn in the rotation -- Javier Vazquez would seem to be a candidate for that given his struggles with a dead arm of late -- or whether Nova would remain in the rotation beyond Monday.

"We just feel that the guys could use an extra day," Girardi said. "Obviously we hope that he pitches very well and he can be impactful for us, but that's getting a little too far ahead right now."

The Yankees' rotation outlook has been murky of late, with Vazquez's dead arm, A.J. Burnett's inconsistency, Phil Hughes' innings limit and Andy Pettitte's injury. Behind CC Sabathia, not a whole lot is certain, which means Girardi can use Nova in a number of ways.

Girardi said he will take a look at shifting the rotation so that Burnett and Vazquez don't pitch on back-to-back days. Before Burnett had a start pushed back because of back spasms on the last homestand, Girardi had used Francisco Cervelli as a personal catcher for those two. The Yankees skipper has been reticent to do that since, because he doesn't want to keep Jorge Posada's bat out of the lineup in consecutive games.

Nova could also be used to take some of the strain off Hughes, who is operating with an innings limit this year. That said, Girardi said he didn't think he would use a six-man rotation.

"I don't think so right now," he said. "We do have an off-day, and we don't have any stretches like this the rest of the year. It might be something we have to look at, but sitting here right now, it's not what I'm assuming we're going to do."

Lineup vs. lefties coming on strong for Yanks

NEW YORK -- The Yankees' lineup may look a little different over the next several days, and not just because it will be missing Alex Rodriguez.

Beginning on Saturday, the Yankees will face left-handed starters in four of their next five games. That means more of Marcus Thames and Austin Kearns in the order, and that's something manager Joe Girardi is happy about.

Thames has feasted on lefties all season, with a .338 average in 71 at-bats entering Saturday. He has gradually moved up the batting order against southpaws, hitting fifth on Saturday against the Mariners' Jason Vargas and batting as high as third last week when Mark Teixeira was out of the lineup. Thames responded with five hits in 10 at-bats in Texas, including a home run.

Thames was batting .370 with a pair of homers and six RBIs in 19 games (11 starts) since returning from a strained right hamstring on July 4. He had hit safely in his past eight starts and 10 of his last 11 entering Saturday's game.

"Getting a healthy Marcus back has helped [against lefties]," Girardi said. "He was a guy that we brought here to play against lefties. It definitely has increased our options."

Kearns, meanwhile, has hit the ground running since joining the Yankees at the Trade Deadline. In 12 games, the veteran was hitting .353 with a home run, three doubles and five RBIs.

"His at-bats have been really, really good," Girardi said of Kearns after he contributed a two-run double in Thursday's 11-5 win over the Tigers. "We're going to see some left-handers, so that's a good thing."

"I'm just trying to have a good at-bat every time up there," said Kearns. "I'm just trying to take the same approach, and if it's good, don't mess with it."

Worth noting

Alfredo Aceves will make his third rehab appearance on Saturday night for Double-A Trenton in Portland, Maine. ... After starting the season 12-12 against left-handers, the Yankees are 12-5 in their past 17 games facing southpaw starters. ... Robinson Cano owned 12 home runs and 28 RBIs off left-handed pitchers entering Saturday, good for second and fifth in the Majors, respectively. The dozen homers, however, were the most in the Majors for any left-handed hitter against lefties. ... The Yankees' Sept. 25 game against the Red Sox will begin at 4:10 p.m. and air on FOX.