TORONTO -- Randy Johnson's first year in New York has not been what he expected, and manager Joe Torre thinks a bad back might be the reason.
Johnson (11-7) lasted just four innings, allowing six runs -- five earned -- and 10 hits. The 41-year-old left-hander also gave up six runs in his last start against Anaheim.
"Every year you have a couple of bad games, but this year has been very frustrating," said Johnson, who has a 4.29 ERA. "The lack of consistency, and what I expect every fifth day has been few and far between."
It was the second-shortest outing of the season for the five-time Cy Young Award winner, who said he "took it on the chin."
Torre thinks the Big Unit has a back injury.
"He may be making some adjustments because of the back," Torre said.
Johnson said his back is fine, but Torre acknowledged the pitcher tweaked it while making a play at first base. Torre said that wasn't the reason Johnson lasted just four innings, though.
"He felt his back a little bit, but that's an ongoing situation," Torre said. "He's got some physical things to deal with."
Torre, Johnson and catcher John Flaherty all said Johnson's slider wasn't effective.
"He's trying to do too much right now," Flaherty said. "He wants to turn this thing around. It seems like the harder he tries the worse his stuff becomes."
Hillenbrand stole home in the third when Johnson tried to pick off Alex Rios at first. Hillenbrand broke for the plate and first baseman Jason Giambi threw the ball into Toronto's dugout, the first of three New York errors.
"It was more or less just an instinct thing," Hillenbrand said. "Seeing the situation, I just took a gamble. It might be a little bit out of the norm but every run against Randy is huge."
Hillenbrand hit an RBI single off Johnson in the first, and his two-run homer off Scott Proctor in the sixth made it 8-4.
Pete Walker (5-3) pitched 2 1/3 innings for the victory.
The Blue Jays also beat Johnson on April 29.
"We're very fortunate to beat Randy twice this year," Hillenbrand said. "Nobody probably expects us to do that and we were able to do that."
Gary Sheffield hit his 23rd homer and drove in two runs for the Yankees.
Plate umpire Marty Foster was carted off the field after being struck by a broken bat in the second. Foster appeared to get hit just above his right knee by the barrel of Jason Giambi's bat. Foster was in obvious pain and remained on the ground for several minutes before being carted off. Laz Diaz moved behind the plate from second base and the game resumed after a delay of about 15 minutes.
"That was ugly," Torre said.
Toronto manager John Gibbons said he heard the injury was just a bruise.
Johnson walked the first batter he faced, Russ Adams, before hitting Reed Johnson with a pitch. One batter later, Hillenbrand hit his RBI single and Aaron Hill followed with a run-scoring single.
Derek Jeter's two-run single and Sheffield's run-scoring single off Scott Downs gave New York a 3-2 lead in the second, but Frank Menechino tied it in the bottom half with a homer and Vernon Wells gave Toronto the lead with an RBI single.
Alex Rodriguez cut Toronto's lead to 5-4 with an RBI grounder in the fourth, but Wells hit an RBI single off Johnson in the bottom half.
Wells singled in the sixth before Hillenbrand hit his 14th homer.
Hillenbrand and Wells each went 3-for-4.
Attendance was 48,088, the largest crowd since the home opener. ... Torre talked to Sheffield, but not about his comments in a magazine about how he's the true leader of the Yankees. "My only concern was that he'd alienate himself from the rest of the club but I didn't see that happen," Torre said. ... Raul Mondesi was the last Toronto player to steal home on April 17, 2001, against New York.