Boston's fading season is now filled with even more uncertainty heading into the trading deadline.
Mark Buehrle pitched 6 2-3 innings to earn his first win in almost two months and Dioner Navarro had three hits and three RBIs to lead the Toronto Blue Jays to their fifth consecutive victory, a 6-1 win over the slumping Red Sox.
"We were well aware of it and wouldn't expect anything less from this fan base that's fully behind us when we're doing good or bad," Boston manager John Farrell said of the chants.
Brandon Workman (1-4) fell behind quickly after being called up from Triple-A to replace trade bait Lester. The All-Star left-hander was originally scheduled to start for Boston, but he was scratched while his name is bandied about ahead of Thursday's trade deadline.
As the Red Sox went down weakly in the ninth, fans remaining from the sellout crowd chanted, "Jonny Lester!"
Workman knew it was an odd start.
"Yeah, a little bit," he said. "But I kept my mind on throwing. I wasn't as sharp as needed to be."
Workman walked the first two batters in the game before they both came around to score. The Blue Jays added three unearned runs in the fifth inning on errors from Workman and third baseman Xander Bogaerts.
Buehrle (11-7) allowed one run on six hits and a walk, striking out two to snap a six-game losing streak that matched the longest of his career. He had not won in nine starts since earning his ninth consecutive victory on June 1.
Toronto has won eight of its last nine games and trails first-place Baltimore by 2 1-2 games.
The game marked a milestone in Boston's woeful World Series title defense, coming a day before the trade deadline and in the middle of a streak in which the Red Sox have lost eight of nine games, fallen into last place and dropped 13 games behind the East-leading Orioles.
After shipping Jake Peavy to San Francisco on Saturday, the Red Sox sent demoted starter Felix Doubront to the Chicago Cubs on Wednesday. Lester, who is due to be a free agent, could follow him; so could John Lackey, who is scheduled to make the minimum next season.
Reliever Andrew Miller struck out the side in the seventh inning in what could be his audition for a contender.
WHO KNOWS WHAT'S HAPPENING?
Miller was standing at his locker about 3 1/2 hours before the game when a group of reporters approached him. Farrell came out of his office after the brief interview was over and jokingly asked the reliever, "What's going on here?" To which the left-hander said, "I don't know."
Miller probably felt like several others on the Red Sox, wondering where they'll be come Thursday night.
LOW RUN OUTPUT
The Red Sox scored four runs in the three games against the Blue Jays, but had plenty of chances Wednesday night when they collected eight hits.
"I think we were 1 for 11 with men in scoring position tonight," Farrell said. "We had some men on base, but, once again, we weren't able to string together base hits."
Blue Jays: Infielder Brett Lawrie, on the disabled list since late June with a broken right index finger, could start rehab games this weekend.
Red Sox: Off Thursday before opening a three-game series with the Yankees. By the time New York gets to town, Boston could be without four-fifths of the starting rotation it started the season with.
Blue Jays: Open a four-game series in Houston, with Drew Hutchinson (7-9) facing Jarred Cosart (9-7).