McCutchen limped off one batter after hitting an RBI double in the third. A five-time All-Star and Pittsburgh's leader in home runs and RBI, McCutchen is day to day.
"I was just taking my secondary lead and my knee kind of grabbed," McCutchen said. "If your knee could get a cramp, that's what it felt like."
Tests performed at the stadium showed no damage, and McCutchen said his knee was feeling better following the game.
"We're moving in the right direction tonight," he said. "I'm walking fine, not limping or anything."
Toronto lost for the first time in seven interleague games.
Making his first start in Canada, his parents' home country, Taillon (7-5) allowed two runs and six hits.
"He really didn't run into any trouble," interim manager Tom Prince said.
Taillon said he was excited to pitch in Toronto, where he watched games as a child. He left more than a dozen tickets for family and friends, while as many as 30 more paid their way in.
"I've got a ton of texts of screen shots of my mom on the broadcast, which is cool," Taillon said.
Taillon left after Toronto put runners at second and third with no outs in the seventh. George Kontos came on and retired the next three batters.
"George picked him up big time," Prince said.
Blue Jays right-hander Marcus Stroman (10-6) allowed four runs, none earned, and four hits in eight innings, snapping a six-start unbeaten streak. The loss was his first since a July 3 road defeat against the Yankees.
Pittsburgh took advantage of two errors by Blue Jays second baseman Rob Refsnyder to score four unearned runs in the third. After making an errant throw to second while trying to force John Jaso on Francisco Cervelli's grounder, Refsnyder failed to touch second base while trying to turn a double play on Adam Frazier's hard shot to third, allowing the Pirates to score their first run.
"That's what you do against good pitchers," Prince said. "They gave us a crack, we took advantage."
Stroman took the blame for not overcoming the defensive miscues.
"I felt like I should have done a better job of buckling down and getting my team out of that," he said.
Jose Bautista hit a solo home run for the Blue Jays, his third in three games after going 18 games without one. Bautista's homer was his 20th, giving him eight straight seasons with at least that many. Carlos Delgado, who did it in nine straight seasons between 1996 and 2004, is the only other Blue Jay to achieve the feat.
Among active players, only Seattle's Nelson Cruz (2009-2017) and Houston's Brian McCann (2008-2016) have streaks longer than Bautista's. Miami's Giancarlo Stanton (2010-2017) has also hit 20 or more in eight straight seasons.
PRINCE TAKES THE THRONE
Usually the bench coach, Prince will manage the Pirates again Saturday because Clint Hurdle is away attending the funeral of late slugger Don Baylor.
Taillon is 4-1 with a 2.12 ERA in six career interleague starts.
Pirates: McCutchen was replaced by Starling Marte.
Blue Jays: C Russell Martin left while warming up for the second inning because of a strained left oblique suffered in his first-inning at-bat. Gibbons said Martin will undergo an MRI on Saturday. "Those injuries are never good," Gibbons said. Raffy Lopez replaced Martin. ... DH Kendrys Morales (illness) missed his second straight game.
Pirates: RHP Trevor Williams (5-4, 4.17) pitched seven shutout innings against Detroit in his previous start. Williams has never faced the Blue Jays, but is 1-0 with a 1.29 ERA in two interleague starts.
Blue Jays: RHP Chris Rowley will be promoted from Triple-A Buffalo to make his major league debut. A former first lieutenant in the United States Army, Rowley began the season at Double-A before moving up to Buffalo, where he went 3-4 with a 2.82 ERA in 10 games, including six starts.
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