MILWAUKEE -- Astros catcher Chris Snyder is one of the few veterans remaining on the team after a flurry of July trades that saw the club deal away Carlos Lee, Brett Myers, Brandon Lyon, Wandy Rodriguez and J.A. Happ. The moves didn't come as a surprise to the 31-year-old catcher.

"You figured there's going to be some guys they would move to get a few more pieces, and that's part of it," Snyder said.

Snyder, who has aspirations to be a Major League manager when his playing career is over, has become a favorite battery mate for the pitching staff, which has gotten much younger than it was at the start of the year. Snyder said the youth movement hasn't changed the way he approaches his preparations.

"I go about my business the same way and prepare the same way," he said. "It doesn't matter if the team is full of crusty veterans or young guys. It's still the same game, and I think at times there's a little bit more of a teaching aspect and just kind of helping some guys out along the way.

"But you've still got to get up here when you get a chance like this and grow up quickly and contribute. Guys that do that are guys that stick around awhile, and the guys that don't, you really don't hear from again."

Castro to start rehab assignment on Friday

MILWAUKEE -- Astros catcher Jason Castro will begin a Minor League rehab stint Friday for Double-A Corpus Christi, manager Brad Mills said. Castro has been on the disabled list since July 8 with right knee effusion, and has had the knee drained of fluids more than once.

Mills was hoping that Castro, who missed all of last season following ACL surgery on his knee, could catch three innings and work his way up to nine innings before being activated. Corpus Christi opens a four-game series Friday in Midland.

"That has not totally been set in stone yet, but that's kind of what we had talked about," Mills said. "If it's not Friday [he begins his rehab], it's going to be fairly soon anyway, to get him out and get him going again."

Castro is hitting .254 with two homers and 20 RBIs this year, but was batting .301 with a .380 on-base percentage in his 83 at-bats prior to his knee injury.

Meanwhile, Mills said shortstop Jed Lowrie -- on the disabled list since July 15 with a sprained right ankle and damage to his nerve -- has begun wearing another leg brace that will allow him to have more range of motion in the knee.

Prospect Paredes migrates to outfield

MILWAUKEE -- With All-Star Jose Altuve entrenched at second base and Jimmy Paredes putting up big numbers as the second baseman for Triple-A Oklahoma City, the Astros have begun to experiment with Paredes in the outfield. He made his debut in left field Tuesday and went 0-for-2.

Paredes played third base for the Astros the final two months of last season, but was moved to second base in the spring because of his defensive shortcomings. That put him behind Altuve on the depth chart, and the club began to discuss moving him to the outfield. He's hitting .324 with 11 homers, 49 RBIs and 31 stolen bases.

"I think he's kind of excited about it, which is nice," Astros manager Brad Mills said.

Paredes, acquired from the Yankees two years ago in the Lance Berkman deal, is athletic enough and has a strong enough arm to play anywhere in the outfield. Astros director of player development Fred Nelson said Paredes will see some time in center, as well as still get reps at second base.

"We're going to begin to work with him a little bit in the outfield," he said. "He's been taking fly balls and things like that, and we're going to play him out there probably in the short term and probably try to get him playing time in center field as well. We'll see how things go."

Worth noting

• Astros outfielder J.D. Martinez, who slipped in the dugout Monday and dinged his elbow, was out of the lineup Wednesday, but was available to play.

• Manager Brad Mills said right-hander Wilton Lopez was available to pitch Wednesday after experiencing some tightness in his elbow playing catch a day earlier. The Astros were going to be without Chuckie Fick, who threw three innings in relief Tuesday.