PEORIA, Ariz. -- The wind got the best of Walter Silva on Thursday in a Minor League game against the Seattle Mariners' Triple-A affiliate.

Silva, who is likely the leading internal candidate for the No. 5 spot in the rotation, left one ball up on Thursday that didn't come back, an opposite-field home run that was no doubt aided by a stiff breeze blowing out to right field.

More than that, though, Silva had trouble at times with his fastball command during his 2 2/3-inning stint that covered 65 pitches and saw the right-hander allow three runs with two walks and five strikeouts.

"The wind got me a little. My fastball started moving a lot more than it usually does," Silva said.

Silva and newcomer Luke Gregerson, obtained Monday as the player to be named later in the Khalil Greene deal with the Cardinals, each pitched on Thursday in front of manager Bud Black, pitching coach Darren Balsley and several members of the front office.

Silva, 32, struck out four of the first five batters he faced before allowing two runs in the second inning on fastballs up in the strike zone. He then allowed an opposite-field home run in the third inning and walked two before leaving.

"What we're trying to do is to get Walter to a certain pitch count and continue to evaluate his stuff," Black said. "He tired after about 60 pitches, which we expected. We're building him up. But I liked what I saw from his fastball and slider."

Gregerson, who flew from Florida where the Cardinals train to Arizona on Monday and reported to workouts the following day, threw one inning on Thursday. He allowed one unearned run, a walk and got an inning-ending double play.

"I was just trying to get some outs ... my sinker was really cutting. It was moving a little more because of the strong winds," Gregerson said.

Gregerson, 24, only threw one slider, which is regarded as his best pitch, but Black liked what he saw.

"The early reports on Luke are that he has a solid fastball and solid slider. I didn't realize that he had so much sink. Part of that was because of the wind, but his ball moved a ton."

Gregerson, who according to Black is in the mix of players trying to win a spot in the bullpen, spent all of last season at Double-A Springfield. He had a 3.35 ERA with 78 strikeouts in 75 1/3 innings.

• Also on Thursday, right-handed pitcher Jae Kuk Ryu was claimed off waivers by the Cleveland Indians.

Ryu, who the Padres claimed off waivers from Tampa Bay on Jan. 15, was 0-1 with a 10.61 ERA in eight appearances this spring.

The Padres now have 40 players in their Major League camp, including 25 on the 40-man roster and 15 non-roster invitees. San Diego's 40-man roster is now at 39.

• Pitcher Jake Peavy makes his first appearance since rejoining the team when the Padres play at 7:05 p.m. PT in Phoenix on Friday night against the A's. Newcomer Shawn Hill, who signed a Minor League deal on Monday, is set to make his first appearance for the Padres in the game.