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09/03/11 6:02 PM ET

Yanks having to manage 'pen workload

NEW YORK -- With the Yankees involved in tight games and a tight race for the American League East title, the business end of their bullpen has received plenty of work recently. With those innings comes subsequent unavailability for many of their relievers.

One day after David Robertson stayed in the bullpen with general soreness, manager Joe Girardi said he likely did not have Mariano Rivera or Rafael Soriano available for Saturday's game against Toronto.

The Yankees have won five of six games, and Rivera has earned the save in each of the team's last four victories. Soriano had also pitched on four of the last five days entering Saturday. Since returning from the disabled list on July 30, he has struck out 12 in 12 2/3 innings and pitched to a 2.84 ERA.

Robertson has been invaluable to the Yankees this season, but the Yankees have been careful not to overwork him. His 58 appearances are tied for 45th in the Major Leagues. In 2010, the 26-year-old right-hander pitched in a career-high 64 games.

"I'm trying to regulate it like we do with a lot of our relievers and not try to work him too much," Girardi said of Robertson. "Sometimes a guy just needs a day. Sometimes the inning that you go through you work really hard, and for whatever reason, you might be a little stiff the next day."

Montero on the board with first big league hit

NEW YORK -- Top Yankees prospect Jesus Montero picked up the first of what he hopes will be many Major League hits with a single to left field on Saturday.

Montero, a September callup, batted seventh and played as the designated hitter against Toronto. With two outs in the sixth inning, he snuck the ball through to left field off Blue Jays starter Ricky Romero.

"Very excited, very happy to be on first base," Montero said. "Thank God that I hit the ball well to shortstop. At first, I thought he was going to catch it. I was like, 'Oh, don't catch it.' But thank God I got a base hit."

Montero said he would give the ball to his father, who was watching on television. Montero's mother moved with him from Scranton, where he had been playing with the Yankees' Triple-A affiliate.

"He saw me on TV a couple of days ago and he was crying," Montero said. "When I give him the ball, it will be a big present for him."

Montero, 21, was signed as a catcher and has played there in the Minor Leagues. But questions remain about his defense. He hit .290 with a .350 on-base percentage for Triple-A Scranton/Wilkes-Barre this season.

A-Rod returns while Teixeira and Jeter sit

NEW YORK -- Alex Rodriguez, who missed the last six games with a sprained left thumb, returned to the Yankees' lineup Saturday, but he was not joined by Mark Teixeira or Derek Jeter.

Teixeira sat out for the second straight game with a bruised right knee suffered when he was hit by an Alfredo Aceves pitch Thursday night in Boston. Jeter received a regular off-day.

In Teixeira's absence, Rodriguez played third and hit in the lineup's No. 3 hole. His ability to play the field cleared the way for September callup and top prospect Jesus Montero to make his Yankee Stadium debut as the designated hitter. Nick Swisher continued to fill in for Teixeira at first base, and Andruw Jones took Swisher's spot in right field. Eduaro Nunez started at shortstop.

Even with Teixeira on the bench for the second straight day, manager Joe Girardi said the level of concern surrounding the injury remained low. Before meeting with the team medical staff, Teixeira said he felt "a little better" than he did Friday, but his knee was still taped.

"It's just getting through the soreness, and the soreness will go away," Girardi said. "It's not like he has a sprained ankle or something. It's a bruise, and that will go away."

Teixeira said after Saturday's game that he hoped to play Sunday.

Rodriguez may not be out of the woods with his injury. He was only cleared to play after running through drills, and Girardi said the Yankees hope the pain doesn't return.

"The injury should heal," Girardi said. "The problems that you run into is that you could have to go after a ground ball, and you could re-aggravate it a little bit. You'd like to be able to say you could control it, not aggravate it, but that's not the way the game works. Hopefully, that that doesn't happen."

Rodriguez, who has also missed time after having knee surgery, has now played in 85 of the Yankees' 137 games. He could sit more as the season winds down.

"I'm sure there are a lot of days where he'll be able to go through and he may not feel anything," Girardi said. "And then there could be that day where he jams his thumb a little bit, that it bothers him. That's the thing when you're dealing with hand injuries -- they come back. So it's just something that we have to check with him pretty regularly, see how he feels, and then we'll go from there."

Bombers bits

• Manager Joe Girardi said the Yankees still plan to trim their rotation to five pitchers on Tuesday. A.J. Burnett and Phil Hughes are both following their normal routine, including throwing their regular side sessions.

• In 75 plate appearances since the All-Star break, Andruw Jones is hitting .333 with a .467 on-base percentage and a .717 slugging percentage. Before the break, he had a .215/.282/.431 line.

Thomas Boorstein is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.