The Blue Jays finally revealed their mystery pitcher for Wednesday night, and he has a couple of tough acts to follow.

Brad Mills has been summoned from AAA Las Vegas to pitch the series finale against the visiting Baltimore Orioles at 7:07 p.m. ET.

Toronto has a chance at a fourth three-game sweep in as many series this season versus the Orioles, owners of the worst record in the major leagues at 31-69.

Mills, 25, will attempt to duplicate the efforts of Brandon Morrow and Ricky Romero, who tossed six and 7 2/3 solid innings respectively for the 52-49 Blue Jays in the first two games.

The left-hander hopes to make a lasting impression as Toronto is expected to return Mills to the Las Vegas 51s after Wednesday's outing to make room on the active roster for outfielder Travis Snider to be promoted from AA New Hampshire.

Mills failed miserably in his only two starts with the big club a year ago as he went winless and allowed four home runs in 7 2/3 to the Philadelphia Phillies while posting an ugly 14.09 earned-run average.

In his most recent start at the Rogers Centre, Mills gave up four first-inning runs to Philadelphia and eight overall in a 10-0 defeat on June 27, 2009.

"Hopefully I'll know what to expect when it happens again, as far as getting to pitch up here," he told reporters at the time. "Get over the nervousness and all that stuff.

"I still know my stuff plays up here. I just have to execute a little better."

Better prepared

Mills appears to have put himself into better position this time around, having gone 3-0 with a 2.00 ERA in his past three starts at AAA. In 16 outings this season, Mills is 7-4 with a 4.13.

The light-hitting Orioles haven't posed much of a threat to any team of late and are in danger of losing their 70th game faster than any Baltimore club since 1955.

"We're trying everything possible and the outcome is the same," interim manager Juan Samuel told reporters. "We just have to right this."

Part of that job will fall in the hands of pitcher, Jeremy Guthrie, who brings a career 3.56 ERA against Toronto into Wednesday's start. He's 4-10 on the season with a 4.46 ERA and just 2-5 in 13 starts against the Jays, including three straight losses at Rogers Centre.

The Orioles have lost 10 of 12 games since the all-star break while the starting pitchers have posted an 8.50 ERA.

They will be happy to leave Toronto, where they have served up five homers, including three to Jose Bautista, who leads the majors with 30 long balls this season.

"I figured I was going to be able to at least hit same amount [of homers] that I usually do, like 10 or 15," said Bautista, whose previous career high was 16. "This is way over my expectations but I'm going to keep going out there and hoping for some more."

The surprising slugger has six homers — along with 15 runs batted in — against the Orioles this season.

"He's just in one of those zones right now," Samuel said. "We've just got to continue to make pitches on him and if we miss, he's taking advantage of them."

The Blue Jays, who lead all of baseball with 154 dingers including 84 at home, have a chance to become the first team since the 1976 Cincinnati Reds to lead the major leagues in home runs in three of the season's first four months.