After two impressive wins, Miller lost for the first time in four decisions on Friday against Texas, as the Rangers rocked him for six runs and five hits in just 1 1/3 innings to drop him to 6-2 to go along with a 5.27 ERA. He had allowed just one run in winning his two previous starts.
"It's disappointing," Miller said. "I felt like I had been throwing the ball well. I had gotten opportunities. I certainly didn't do that tonight. From here, you dust yourself off. I'll be prepared next time I get an opportunity, but pretty poor performance tonight."
This will be his first-ever start against the Blue Jays.
Toronto will counter with left-hander Ricky Romero, who lost for the first time in seven decisions on Saturday to New York. Romero actually left with the lead in that one, but ended up getting charged with five runs and eight hits in 6 2/3 innings, as he fell to 13-10 on the year and saw his ERA rise to 2.97.
The 26-year-old is now 6-1 with a 2.56 ERA in his past nine starts, and he has recorded a quality start in all but seven of his 28 outings this season.
"I thought I did a pretty good job of battling," Romero said. "Early on, I think I was not making good pitches, I didn't have a good cutter going today. So we went to other pitches, we had other stuff working, and I thought we did a pretty good job."
Romero lost to the Red Sox the last time he faced them and is just 2-6 in 11 starts against them with an 8.08 ERA.
The Red Sox wasted a golden opportunity to gain some ground on the New York Yankees in the American League East on Wednesday, as Edwin Encarnacion hit a three-run, go-ahead double with two down in the eighth inning and Toronto eked out an 11-10 win.
The Red Sox led 8-6 entering the frame and starter Tim Wakefield was in line for his 200th career win, but Daniel Bard (2-6) walked home two runs before Encarnacion ripped a 3-2 fastball from Matt Albers into the gap in right- center.
"I think the most underlying thing is our approach late in the game," Blue Jays manager John Farrell said. "We continue to grind out at-bats."
Adrian Gonzalez's homer and Marco Scutaro's RBI single in the top of the ninth made it a one-run game, but pinch-runner Mike Aviles was caught stealing with two outs, securing a win for Shawn Camp (4-3) and a save for Frank Francisco, his 13th of the season.
Jacoby Ellsbury hit a three-run homer for the Red Sox, who have lost five of seven and trail the Yankees by 2 1/2 games.
Wakefield allowed five runs -- four earned -- over five innings but was in line for the win courtesy of Boston's early offense and Jays starter Brandon Morrow's equally ineffective turn.
The Red Sox have beaten the Jays in nine of 15 matchups this season.