The Reds addressed their biggest offseason need on Saturday, acquiring the right-handed starter from San Diego for a package of four players that includes two top prospects.
Cincinnati gave up infielder Yonder Alonso and catcher Yasmani Grandal -- both first-round picks -- along with starting pitcher Edinson Volquez to get the 24-year-old Latos, who initially will move into the No. 2 spot in the rotation behind Johnny Cueto. Latos went 9-14 with a 3.47 ERA for the Padres last season, finishing among the NL leaders in ERA and strikeouts.
The trade surprised Latos, who said the Padres had indicated to him that he wouldn't be going anywhere.
"A little bit of shock and a little bit of excitement," Latos said, describing his reaction. "Shock because literally I wake up and I'm traded. Excitement because I'm excited to join a club that's got a lot of talent and a lot of potential. I'm excited for new scenery."
The Reds wanted him so badly that they were willing to give up a lot.
"To acquire a pitcher who is ready to fit into the top of a rotation, you have to give up talent," general manager Walt Jocketty said.
Latos joins a rotation that includes Cueto, Bronson Arroyo, Mike Leake and Homer Bailey. The rotation was a problem last season, with Cueto opening the season on the disabled list and Arroyo struggling with mononucleosis that he contracted during spring training.
Heading into the offseason, the Reds needed to get another top starter and a closer to replace departed Francisco Cordero. They think they've filled their first need.
"When we have Cueto and Latos at the top of our rotation, I think people are going to take notice," Jocketty said.
Latos tied a major league record by allowing two or fewer runs in 15 consecutive starts in 2010. Last season, he held right-handed batters to a .204 average and made 20 quality starts, tied for most on the Padres, who like their pitching depth.
"Mat, with all his success, I think grew up in a hurry in the big leagues and is probably going to do very well in Cincinnati," Padres general manager Josh Byrnes said. "We do have a good group of pitchers. We have a very good group in Double-A coming up behind him. It was a tough trade to make, but ... we have a huge chunk of talent we have put in the system the last couple of years and ultimately I think that's our best path to success."
Alonso, the seventh overall pick in 2008, didn't have a place to play with Joey Votto a mainstay at first base. The Reds moved him to left field briefly last season, but he struggled defensively. The 24-year-old Alonso batted .330 with five homers and 15 RBIs in 47 games. Byrnes said he'll be a leading contender for the starting job.
Volquez was coming off a disappointing season, going 5-7 with a 5.71 ERA. The Reds got him from Texas in the trade for Josh Hamilton in December 2007. Volquez went 17-6 with a 3.21 ERA in 2008, when both he and Hamilton made the All-Star teams. Volquez needed reconstructive elbow surgery the following year and has never gotten back into form.
Grandal, the 12th overall pick in 2010, batted .305 with 14 homers and 68 RBIs at Class A, Double-A and Triple-A last season, making a quick rise through the farm system. He was slotted behind catcher Devin Mesoraco, a first-round pick in 2007 who made it to the majors last season and played in 18 games.
Jocketty said Reds were willing to trade Alonso and Grandal because they were stuck behind other players at their positions.
The Reds also gave up right-handed reliever Brad Boxberger, who went 2-4 with 11 saves and a 2.03 ERA last season at Double-A and Triple-A. Jocketty said Boxberger was the final piece in finishing the deal.
"It was very tough giving him up," Jocketty said. "We feel he was really starting to come into his own in the second half of the year. I don't think we would have been able to make the deal if he wasn't part of it."
Latos moves from a pitcher-friendly ballpark to Great American Ball Park, one of the most homer-friendly in the majors. He said he learned during a rough patch early last season that he couldn't let a ballpark's dimensions affect how he pitched.
"Earlier I was trying to be too fine with my pitches instead of just attacking with my strengths," Latos said. "I learned to just trust myself and go after hitters regardless who it is or where we are. Cincinnati is said to be hitters' park. Philly is the same way. That doesn't mean where you're at or the park you're in to change your pitching style."