TORONTO -- Mariano Rivera has blown three saves in his last six appearances, and that rare September swoon was reason enough to send the Yankees closer into the bullpen on Monday afternoon, working on fixing a mechanical issue.

One day after Rivera coughed up a one-run lead to the Red Sox -- an appearance during which Boston stole four bases with him on the mound -- the 40-year-old was trying to get everything back to normal during a session with pitching coach Dave Eiland.

"We're working on it. You have to keep working," Rivera said. "It's not like things are going to just happen and be there all the time."

Yankees manager Joe Girardi said that Eiland believes Rivera is throwing slightly off to the side of the ball, which has hurt his location and reduced the amount of cut on his pitches.

Catcher Jorge Posada said that some of Rivera's pitches in Sunday's appearance were up too much, like Ryan Kalish's one-out single to center field in the ninth inning. Kalish stole second and third base, scoring the tying run on a Bill Hall hit.

"It's frustrating," Posada said. "You want Mo to sail through -- you've got a 2-1 game, and they did a good job of really getting to some of his pitches and disrupting his tempo to the plate."

Girardi said that he believed the stolen bases -- two by Kalish, two by Hall -- were on Rivera, who has struggled some this year when forced to go to the slide step with runners on base.

"He was just slow, and I think his timing was predictable," Girardi said. "It did happen last night and I guess it shows that Mo is human. ... I think a lot of them were [off Rivera]. Actually, he's been really good about it. For whatever reason last night, he became a little predictable."

With many scouts in attendance at Yankee Stadium on Sunday, as well as an audience at home watching the nationally televised broadcast, Rivera said he couldn't be stunned if teams continued to try what worked so well for the Red Sox.

"Anybody can try whatever they want," Rivera said. "They have to make sure they get there. Those things don't bother me at all. As long as I execute my pitches and do what I have to do, I'm OK with that. It's not like I'm going to try something new -- been there, have done it. What am I going to see that's different, that I haven't seen?"

Rivera owned a 1.03 ERA after he was summoned to pitch two innings in a Sept. 10 extra-inning game against the Rangers in Texas. Girardi noted that Rivera has not had the same location and cut since then, as Rivera has blown three of six save opportunities -- after blowing just two in the previous 5 1/2 months.

"You want him to get his mechanical things worked out, and if he gets them worked out, you figure Mo is going to be Mo," Girardi said. "I don't see a big dropoff in velocity. The velocity has been the same all year, so physically I think he's OK. I just think he's a little out of whack. We've got to get him right."

Rivera bowed out of the All-Star Game in July, citing injuries to his right knee and left oblique muscle, and he said those ailments are still irritating him months later.

"I don't think when you play 162 games, you're not going to have problems," Rivera said. "I wish somebody would tell you that. Me, I won't tell you that. But you work with that. Everybody would love to be 100 percent and play, but I don't think there's one player that tells you that. Bumps and bruises, you have them, but you have to play with those things."

Posada eager to match up with Burnett

TORONTO -- Jorge Posada was less than pleased last year when the Yankees opted to pair another catcher with A.J. Burnett during the postseason, and the 39-year-old veteran is hoping he will get a chance to avoid a repeat in 2010.

Posada said Monday that he was disappointed that manager Joe Girardi did not pencil him into the lineup against the Blue Jays, instead keeping Burnett with backup catcher Francisco Cervelli.

"I want to be back there," Posada said. "I thought I was going to get the chance today. It didn't happen. [It was a] tough game yesterday, and it's disappointing that I'm not back there again."

Unlike last year, when Girardi kept Burnett with understudy Jose Molina to winning results, Girardi said that he is heavily considering putting Burnett and Posada together in the playoffs. Girardi said he was leaning toward catching Posada on Monday before the Yankees went into extra innings against the Red Sox on Sunday.

"In the back of my mind, before we went through last night, I was probably going to start him tonight," Girardi said. "But with the long game -- getting in at 4 o'clock, I thought it was probably in the best interests not to."

Posada said that he thought he might be in the lineup Monday after talking to Burnett and pitching coach Dave Eiland this week. He could be behind the plate if Burnett makes a start this weekend at Fenway Park.

"I want to be able to be prepared and be back there, knowing what he wants to do and just see it, and have a good game back there, so he can be comfortable with me in the playoffs," Posada said.

Girardi: Playoff celebration up to players

TORONTO -- With the Yankees' magic number to clinch a playoff spot sitting at one entering play on Monday, manager Joe Girardi is leaving it up to his players to decide if they should celebrate if and when they punch their ticket to the postseason.

"If they want to celebrate, I respect that," Girardi said. "They worked very hard this year and they should do what they want."

The tight quarters of the visiting clubhouse at the Rogers Centre played host to a Yankees celebration in 2006, when the Yankees lost to the Blue Jays but hung around to see the Red Sox lose to the Twins, clinching New York's ninth consecutive American League East title.

Girardi said that he didn't know if the players had anything similar in the works, saying, "You don't know until it possibly happens. It'd be a nice thing to see."

Worth noting

Yankees manager Joe Girardi said that he is keeping the rotation on turn, meaning CC Sabathia continues to be listed as Tuesday's probable starter. That may change if the Yankees clinch a playoff spot Monday. ... The Yankees finished the 2010 home regular season with a total attendance of 3,765,803, averaging 46,491 per game. Their overall home attendance and per game average attendance both lead the Majors, and surpassed the Yankees' home attendance figures for the 2009 regular season (3,719,358 total; 45,918 per game). ... According to the Elias Sports Bureau, shortstop Derek Jeter played in his 1,377th regular season victory on Sunday vs. Boston, surpassing Mickey Mantle (1,376) for the most in franchise history. The only active player who has played in as many wins as Jeter is Omar Vizquel (1,479).