CLEVELAND -- The Blue Jays saved their biggest surprise of Spring Training for the final day of camp, and when it finally arrived, it came as both a shock to those around baseball and the pitcher himself.

Right-hander Joel Carreno was getting ready for another season at Double-A New Hampshire when the phone rang. He was being promoted to the Major Leagues with just two days to go until Opening Day.

The decision to start Carreno on Sunday in Cleveland caught the hurler completely off guard, as he'll now technically open the year as Toronto's No. 3 pitcher, despite having just 15 2/3 innings of big league experience under his belt.

"I was surprised, because they [had] sent me down," Carreno said. "I was surprised, because I was already in Double-A and they called me in the morning and said I was called up.

"I have to do a good job for them. I don't [want] to make them think, 'He has to go back to the Minor Leagues.' So I have to do the best I can do here."

Carreno officially arrived at Spring Training in February with a chance to make the Blue Jays' bullpen. He was included among the list of candidates, but with lots of veterans on the staff, it was going to be an uphill -- if not impossible -- battle.

Toronto already had Sergio Santos, Francisco Cordero, Darren Oliver, Casey Janssen, Jason Frasor, Luis Perez and Carlos Villanueva penciled in as the seven relievers. That eventually led to the decision to cut Carreno with more than two weeks remaining in camp.

Carreno returned to the Minors, where he went back to his role as a starting pitcher. That's the position he filled last season in New Hampshire, where he was 7-9 with a 3.41 ERA while striking out 152 in 134 2/3 innings.

The hope of Carreno making the big leagues in April was dashed, but the organization assured him it wouldn't be long until he was back with Toronto. Carreno just never knew at the time how fast that promotion would occur.

"They said I had to do a couple of things for being a starter," Carreno said. "I had to work on a couple of pitches and I had to go back to the Minors to work on those pitches. Then, they called me and I'm here now.

"I'm working on my changeup and my front side. Sometimes I go side to side with my pitches and my pitches fly into the strike zone and the hitters take advantage."

Carreno's surprise promotion was a byproduct of the problems in Toronto's rotation that began with two weeks left in camp. The first major blow came when No. 5 starter Dustin McGowan was shut down because of plantar fasciitis in his right foot.

That left Kyle Drabek and Aaron Laffey fighting for the final spot on the staff, but another job opened up when No. 3 starter Brett Cecil began to struggle during his last three starts in the Grapefruit League season.

Cecil's woes began with a four-run outing that included five walks in just 2 2/3 innings against Tampa Bay. Then there was a nine-run performance in four frames against the Tigers on Monday. Cecil's lack of velocity, and more importantly his lack of command, forced the Blue Jays' hands and had them searching for another option.

With Laffey struggling and prospect Drew Hutchison not quite ready for the next level, Toronto turned to Carreno to fill the gaping hole.

"He showed us last year when he came up [that he was] very composed, didn't back away from the Major League environment or any hitter he faced in a given situation," Blue Jays manager John Farrell said of Carreno, who allowed just two earned runs in 11 relief appearances last year. "We like his stuff, he has been a very successful starter up through Double-A.

"I know he hasn't started a game above Double-A in his pro career, but when you factor in that he already has been exposed to the Major League environment, he has three very good pitches, those are the things we looked at and said, 'You know what, this is a guy that is very deserving of the opening that we have.'"

Carreno signed with the Blue Jays as an amateur free agent in 2004 at the age of 17. He slowly rose through the ranks, and in 2010 began to put himself on Toronto's radar by posting a 3.73 ERA in 27 games with Class A Dunedin.

The 25-year-old followed that up with a strong season in New Hampshire, which earned him a late-season callup to Toronto. Carreno's no-fear approach and ability to throw strikes quickly made him a favorite of Farrell, who went out of his way last year to praise the Dominican native.

Now the next step of Carreno's career begins when he takes the mound on Sunday afternoon against Cleveland. He can be forgiven if nerves play a factor in his first start in the Majors, but it's something he doesn't anticipate happening.

"I feel like I'm ready ... I'm not nervous," Carreno said. "The first time I was called up, I was a little nervous, but everything is good right now."