Dan Straily eyes his first win in more than a month and a series victory over the Toronto Blue Jays on Monday afternoon when he takes the hill for the Oakland Athletics in the finale of a four-game series.

Following a win over the Pittsburgh Pirates on July 9, Straily was sent back to Triple-A Sacramento before returning to the A's at the end of the month. He has lost all four starts since his return, falling to 6-6 with a 4.41 earned run average in 18 starts this year with the Athletics.

Though the right-hander has been charged with two earned runs or less in three of those four games, he has not pitched past the fifth inning in three straight. Straily logged 4 2/3 innings in a 5-0 setback to Toronto on July 30, charged with five runs -- two earned -- and giving up a pair of homers.

Straily was then lifted after four innings and 75 pitches in Tuesday's 3-1 setback at Cincinnati. He yielded two runs on six hits and a walk.

The 24-year-old is 0-1 with a 2.53 ERA in two career meetings with the Blue Jays.

The Blue Jays shook up their rotation ahead of this finale, pushing scheduled starter Josh Johnson back to Wednesday in part because of some tightness in his right forearm that he experienced in his last start, and moving J.A. Happ up a day to pitch on Monday.

Happ will make his second start following a three-month absence due to a skull fracture sustained when he was hit by a line drive against Tampa Bay on May 7. Though his return to the hill last Wednesday was a great sight, the lefty experienced some issues on the mound in a no-decision.

Despite getting staked to an early lead, Happ did not factor into a 9-7 loss as he allowed seven runs -- six earned -- on seven hits and three walks over four-plus innings.

"It's obviously not how I wanted it to go," Happ said. "We should have won that game. We scored seven runs early. I wasn't able to keep us holding onto that."

The 29-year-old is still on normal rest due to an off day last Thursday and is 2-2 with a 5.84 ERA in eight starts this season. He will make his first career start versus Oakland, having faced them twice before in relief.

Happ will try to pitch the Jays to a split of this series after Oakland pulled away late for a 6-4 win on Sunday.

Alberto Callaspo hit a go-ahead two-run double during a three-run eighth inning, with his drive to left tipping off the glove of Emilio Bonifacio. Chris Young added a pinch-hit RBI single in the frame.

"They just ended up getting a lucky one there with two outs," Jays infielder Brett Lawrie said in reference to Callaspo's hit. "That kind of stung us a little bit."

Brandon Moss slugged a two-run homer for the Athletics, who remained a game behind the Texas Rangers for first place in the AL West.

Grant Balfour earned his 30th save of the season the hard way, giving up a run in the ninth and leaving the bases loaded before finishing things off. That gave manager Bob Melvin the 700th win of his career.

"Never a dull moment," Melvin deadpanned. "Excruciating. We found a way to win but it wasn't pretty."

Melvin sent Young up to pinch-hit for Coco Crisp, who has a nagging left wrist injury and could rest today. Catcher Derek Norris is also likely to get a break as he deals with back spasms.

Jose Reyes and Maicer Izturis drove in a run each for the Blue Jays, who dropped their third game in four.

Toronto has won five of the last eight meetings going back to 2012.