OAKLAND -- Since arriving from Houston in a 10-player trade on July 20, left-hander J.A. Happ found himself in the bullpen, which is an unfamiliar role for a pitcher who's been a starter his whole career.

Blue Jays manager John Farrell had said that the team was discussing ways to get Happ into the starting unit, whether by going to a six-man rotation or simply by replacing one of the current starters should he falter.

After Friday's game, the move was made. The team demoted left-hander Brett Cecil after his start against the A's in order to make room for Happ, who will make his rotation debut on Thursday in Tampa Bay.

"He's an established Major League starter," Farrell said. "We acquired him to do that. He remained patient while we had to go through and sort some things out. And his opportunity's here now."

One potential issue is the condition of Happ's arm. He hasn't started a game since July 16. And with right-hander Brandon Morrow expected to be on limited pitch counts when he returns from a strained left oblique in two or three weeks, the Jays wouldn't want to be in the position of having two of their starters unable to last long due to arms that aren't properly conditioned.

But Farrell expressed confidence that Happ will be able to build his arm back up rapidly as he returns to starting, perhaps mitigating that concern.

Happ wasn't great in his relief role, allowing four runs and walking five batters in seven innings over four appearances. But Farrell said he was taking those numbers with a grain of salt.

"The evaluation of him in a reliever role, good or bad, is tempered with that this isn't the role that he's accustomed to," Farrell said. "He's a guy that's going to come in and establish his fastball as a starter and establish the rhythm of the game. In a relief role, we've seen he hasn't necessarily given in, and has continued to try to make pitches.

"I think ultimately, personally, I would reserve judgment until seeing him in a starting role."

Cecil sent down as Jays make flurry of moves

OAKLAND -- Carlos Villanueva and Brett Cecil have filled in admirably to help stabilize a Blue Jays rotation decimated by injury.

But the question hanging over their heads is what will happen to each long-term. Starters Brandon Morrow and Drew Hutchison will return from the DL at some point this season, and Blue Jays manager John Farrell has made no secret of the fact that he's looking to get recent acquisition J.A. Happ into his more natural starting role at some point soon.

For Cecil, that question was answered after his start on Friday night. Though he had pitched decently in his last three outings, the left-hander gave up four runs in five innings against the A's, and that was enough to warrant a demotion to Triple-A Las Vegas to make room for Happ in the rotation.

Farrell said Cecil will continue to start for the 51s, as he did for Toronto, even though Farrell hinted before Friday's game that Cecil's propensity for getting left-handed hitters out could give him a role in the big league team's bullpen if he lost his rotation spot.

Villanueva's spot is clearly more secure, and Farrell was more direct when addressing the right-hander's future, should he eventually leave the rotation.

"Based on our experience in the last year and a half with [Villanueva], I think he's a very valuable pitcher to be able to provide a swingman role," Farrell said. "And that's not to say he's not a capable starter, but the thing that we can't overlook is the durability on a long-term basis.

"There's a point where the physical component has got to be monitored very closely."

In addition to demoting Cecil after Friday's game, the Blue Jays designated reliever Andrew Carpenter for assignment. The right-hander had a 5.00 ERA in six games for Toronto.

Those moves cleared room for the call-ups of right-hander Jesse Chavez and infielder Adeiny Hechavarria from Las Vegas. Farrell said Chavez, who has accrued 20 1/3 innings with the Blue Jays this season, will be used in a long relief role.

The 23-year-old Hechavarria will be making his Major League debut when he appears for Toronto. He'll sub for the injured Brett Lawrie at third base for the time being, and can also play the middle infield.

Worth noting

• Outfielder Moises Sierra is perhaps the only Blue Jays player who can claim success against Dan Straily, the A's rookie starter on Friday night. Sierra homered off Straily when both were in the Minors in July.

Despite that, Farrell said that he wanted to stay true to his platoon, electing to keep the left-handed-hitting Anthony Gose in the lineup against Straily, a right-hander.