© 2011 MLB Advanced Media, L.P. All rights reserved.

03/29/11 3:06 PM ET

Shelved Latos significantly improving

PEORIA, Ariz. -- The Padres added Minor League right-hander Samuel Deduno to the 25-man roster and officially placed Mat Latos on the 15-day disabled list on Tuesday as the club played its final Cactus League game of the spring against the Brewers at Peoria Stadium.

Latos has a strain of his right shoulder, but the good news is that he is significantly improving, manager Bud Black said, and will travel with the team to St. Louis for the season opener. If everything goes as planned, Latos will throw off the mound on Thursday prior to the game against the Cardinals at Busch Stadium.

"Latos is doing well," Black said. "He'll play catch today and probably tomorrow, and if things go well, hopefully a side session on Thursday in St. Louis. But he's doing much better. We think he's turned the corner in regard to the inflammation."

Latos last threw against the White Sox here on March 21 and reported soreness in his shoulder two days later. The White Sox scored three runs in the first inning that night without recording an out before Latos settled down to pitch into the fifth inning.

Latos struggled this spring, allowing 10 earned runs, 16 hits and nine walks over 10 innings in his four starts.

Despite his problems that night, he said that he felt just fine after the 90-pitch outing.

"I feel amazing. I feel great," Latos said. "I feel like I'm one step closer to where I need to be. It's obvious I wasn't putting my breaking pitch over. But my fastball had life. My baseball had movement on it. Even after 90 pitches, I feel great."

What occurred between that game and the next two days is a matter of conjecture.

"I don't want to put words in his mouth, so it's probably best to ask Mat," Black said. "You're right, he did say he felt great. But [from] that day until two days later, the inflammation built up."

Asked if he thought Latos had been trying to pitch through the problem all spring, Black added, "His conversations with me through the spring were that he was fine. He's like a lot of players. They want to play. If something was occurring through spring, he didn't let us know. He's always been pretty honest with us about how he feels, and he was honest about how he felt a couple of days later."

Latos, 23, is considered to be one of the top young hurlers in the organization and is beginning his second full Major League season. Last year he went 14-10 with a 2.92 ERA, but was 13-3 with a 1.64 ERA in 22 starts from May 1 to Sept. 7 before fading toward the end.

Deduno, 0-1 with a 6.43 ERA in six relief appearances this spring, was selected for the Opening Day roster because of his ability to be used as a long man out of the bullpen. He has four games of Major League experience from last season with the Rockies.

Black said that right-hander Dustin Mosley will be used as a starter, in the mix with Tim Stauffer, Clayton Richards and Aaron Harang. Mosley, who was 4-4 with a 4.96 ERA last year in 16 appearances (nine starts) for the Yankees, is slated to start the third game of the season, on Sunday in St. Louis.

By Major League rules, players placed on the DL can be backdated 10 days from the start of the season, to March 22, which was done with Latos and a host of other injured Padres. If all goes well, Latos would be eligible to come off the DL next Wednesday in San Diego, where the Padres are playing their second home game of the season against the Giants.

Because of three early off-days, the Padres don't need a fifth starter until April 11, at home against the Reds.

In other news, the Padres made a Minor League trade on Tuesday, sending Class A first baseman Allan Dykstra to the Mets for Double-A reliever Eddie Kunz. Dykstra, a San Diego product out of Rancho Bernardo High School, was a first-round selection (23rd overall) in the 2008 First-Year Player Draft and was a questionable choice from the very beginning because of a degenerative hip condition. The right-handed Kunz went 7-8 with a 5.34 ERA in 42 appearances (12 starts) last season for Double-A Binghamton.

Barry M. Bloom is national reporter for MLB.com and writes an MLBlog, Boomskie on Baseball. Follow @boomskie on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.