Warren's scoreless start closed out by Robertson

HOUSTON -- David Robertson heard the boos as soon as his spikes sank into the outfield grass, and he immediately understood. With a ninth-inning save situation on the scoreboard, he was not exactly the most popular choice to trot out of the bullpen.

Those clamoring to see Mariano Rivera take the mound were unaware that the all-time saves leader had proclaimed himself unavailable to pitch. Robertson answered the call in his place, recording three outs to secure a 3-2 Yankees victory over the Astros on Friday night at Minute Maid Park.

"I did not take any of the boos personally," Robertson said. "I can understand why the fans really want to see Mariano. We're in the final three games now; the fans hope to see him pitch again. We'll see what happens."

Rivera's final Yankee Stadium appearance on Thursday was choreographed about as perfectly as possible, and Yankees manager Joe Girardi has left it up to the retiring 43-year-old to determine if and when he appears against the Astros in his last weekend as a big leaguer.

On this night, Rivera told Girardi that he was not ready to play. Rivera is kicking around the idea of fulfilling his dream of playing center field during this series, and there is a chance he may be able to improve on his career total of 652 saves.

"I'll talk to him again tomorrow," Girardi said. "He was not available today. I don't know if he'll be available tomorrow. I'll see what he wants to do. I'll check with him every day. He has a chance to make up his mind every day."

The Yankees snapped a four-game losing streak as Adam Warren pitched five scoreless innings and David Adams slugged a two-run double, sending the Astros to their 13th consecutive defeat.

Making his second start of the year, Warren shifted from his usual long-relief role and held Houston to just two hits and struck out four in what he believes could be a springboard toward competing for a rotation slot next spring.

"I think I've learned and proven to myself that I can pitch at this level," Warren said. "I just wanted to go out there, finish strong and end on a good note. It's been kind of an up-and-down season for me, and to finish on a good note is good for me."

The contest included a brief ceremony in the fifth inning paying tribute to Andy Pettitte, who will make his final career start on Saturday. Astros president Reid Ryan presented Pettitte with a framed jersey from the hurler's 2004 season with Houston.

"It was great," Girardi said. "Andy's from here. He had some important years here, so I thought it was great that he was recognized, and [Saturday] should be special."

Girardi sprinkled members of the Yankees' bench throughout his lineup as something of a reward for his reserves. They produced three runs (two earned) in 5 1/3 innings against left-hander Brett Oberholtzer, doing all of their scoring in the fourth inning.

Mark Reynolds laced a run-scoring single to left field, a play that third baseman Matt Dominguez committed a throwing error on, and Adams -- who had not played since Sept. 10 -- pelted the right-field wall with a two-base hit that brought a pair of runs home.

"For a guy who hasn't had a lot of playing time and hasn't really had any at-bats, it was a huge hit," Girardi said. "He made some good defensive plays, too."

The Astros scored twice in the seventh as Joba Chamberlain struggled. Inheriting a two-on, two-out situation from David Phelps, Chamberlain's first pitch to pinch-hitter Brett Wallace was ripped onto the center-field hill for a two-run double.

"I was just trying to be aggressive early in the count and get something I could drive," Wallace said.

Jonathan Villar rocketed Chamberlain's next offering into left field for a single, and Chamberlain issued a walk to load the bases before escaping on a flyout.

Girardi said that Chamberlain, a free agent after the season, never seemed to have recovered from a rib-cage injury earlier this year. Chamberlain said that he has not given much thought to the idea that he could be playing his final days in a Yankees uniform.

"I haven't pitched good enough to be out on the mound sometimes," Chamberlain said. "When you get a chance, you have to take advantage of it. Sometimes I have and sometimes I haven't."

Robertson had more positive topics to discuss, saying that the opportunity -- his career-high third save of the year -- was good practice. He is the favorite to inherit the closer's job, but Robertson said that he is not considering that to be a done deal by any measure.

"I don't feel like any of the passing of the torch has been done, because I don't know what's going to happen next year," Robertson said. "I haven't been told anything. I closed out tonight's game, but that's tonight. I don't know what's going to happen next year."