"If we want to make the playoffs, we've got to be better," Pettitte said. "We stink right now, for the most part. As a team, we've kind of stunk it up here lately and we've got to play better."
The Yankees ended the first half of the year by losing three of four against the Pirates and Blue Jays. Still, New York's 50-45 record is an improvement on a year ago, when they went to the All-Star Game at .500.
Pettitte's teammates agreed there was room for improvement, but didn't feel so bad about the Yankees' fortunes.
"Today was a tough day," catcher Jorge Posada said. "We got outpitched, but I think we're going in the right direction."
Shortstop Derek Jeter said the key is consistency.
"We've been a little bit inconsistent," Jeter said. "We just need to find a little bit more consistency here."
A rash of injuries has forced 17 Yankees onto the disabled list already this season. With that in mind, first-year manager Joe Girardi knows his situation could be worse.
"We could be buried, but we're not," Girardi said. "I think we're in a decent position to make a run. We need to get everyone back and healthy and just put streaks together."
Pitching on three days' rest for the third time in his career, Burnett (10-8) allowed one run and six hits, walked one and struck out eight. The right-hander is 3-0 with a 3.00 ERA when pitching on three days' rest.
"He wanted the ball and he was determined," Blue Jays manager Cito Gaston said. "You could see it in his eyes from the first pitch that he was going to have a good day."
Jason Giambi spoiled Burnett's shutout bid with a solo home run in the ninth, his 19th. Posada followed with a single before B.J. Ryan replaced Burnett and got Robinson Cano to ground into a double play to record his 18th save in 20 opportunities.
Toronto won for the fifth time in six games to improve to 47-48 at the break.
Burnett, who has won four of his past five, improved to 5-2 in eight career starts against New York.
"I was free and easy," Burnett said. "I got ahead quite a bit. Once I was able to find the hook, it helped out tremendously."
The Yankees did little else to threaten Burnett. Bobby Abreu doubled to begin the fourth and, two outs later, Posada was hit by a pitch, but Cano grounded out to first.
Abreu and Alex Rodriguez had back-to-back one-out singles in the sixth, but Giambi flied out and Posada struck out.
"He never got out of his rhythm," Girardi said of Burnett. "He located the ball all day. He elevated the ball when he had to, he was able to get an inch or two off the plate when he had to. He was outstanding today."
Pettitte came in having won seven of his past eight decisions, but took the loss in this one after allowing four runs and eight hits in six innings. Pettitte (10-7) walked one and struck out six.
All the scoring came in the second, when Kevin Mench led off with a double and scored on a single by Scott Rolen. After Adam Lind walked, Scutaro tried twice to bunt but failed, then drilled a 1-2 pitch over the wall in left for his third homer of the season.
"It doesn't happen often, but it happens once in a while," Gaston said. "Thank goodness it happened today for us."
Pettitte was surprised Scutaro was able to hit a sinking cut-fastball out of the park.
"The pitch wasn't even going to be a strike," Pettitte said. "Scutaro went down and got it and lifted it. I don't know if he was looking for it or whatever."
Last April 15, Scutaro beat the Yankees with a walk-off, three-run homer against Mariano Rivera.
Rolen doubled to begin the fourth and went to third on Lind's single, but was thrown out at the plate by Abreu when he tried to score on Scutaro's fly to right.
Toronto finished with four doubles in all, and five of the Blue Jays' nine hits were for extra bases.
Jeter batted in the leadoff spot for the second straight game and finished 0-for-4 with two strikeouts, snapping a 10-game hitting streak. Girardi said Jeter will continue to lead off until Johnny Damon (left shoulder) returns from the disabled list. Damon is eligible to come off the DL next Sunday.
Posada caught for the second time in three games but surrendered two stolen bases. Posada, who missed 32 games with a right shoulder injury earlier this season, has thrown out just three of 35 runners but feels his arm is improving.
The Yankees began wearing black armbands on their left sleeve Sunday in honor of former player Bobby Murcer, who died Saturday. They will continue to wear them for the rest of the season. ... The three-game series drew 131,295 fans to Rogers Centre. ... RHP Mike Mussina will start against Oakland on Friday, the Yankees' first game following the All-Star break. He will be followed in the rotation by RHP Joba Chamberlain, Pettitte, RHP Sidney Ponson and RHP Darrell Rasner. ... Girardi said OF Hideki Matsui (left knee) could rejoin the team during the Oakland series that follows the All-Star break. ... Yankees RHP Phil Hughes (broken rib) was fine one day after throwing 25 pitches in his first bullpen session Saturday at New York's minor league facility in Tampa, Fla. He is scheduled for another bullpen session Tuesday.