HOUSTON -- Shortstop Ronny Cedeno was out of the lineup for a second straight game Friday against the Astros because he is dealing with a left shoulder impingement.

Cedeno said he's not sure how the injury occurred but that he woke up this morning sore. He's been evaluated by doctors in Houston and said he expects to only miss a few days.

"I woke up this morning and I felt sore," Cedeno said. "I can take ground balls but I can't swing."

Cedeno has never had a problem with this shoulder before. Manager John Russell said he'll know more after receiving doctors' reports.

Starting in his place for the second consecutive game was Argenis Diaz, who made his first career start Thursday against the Padres. He went 1-for-2 with an intentional walk.

"He played a nice game," Russell said. "He didn't make a strong throw on the error, but he's a defensive player."

Walker continues to shine at second

HOUSTON -- Manager John Russell said he's not surprised that second baseman Neil Walker's transition from third base to second base has gone so smoothly. Russell said he saw that potential in Spring Training.

"I knew second base was going to be a position he could play," Russell said. "He's a good athlete. Again I wouldn't say surprised, but it's nice to see he's picked it up quicker than I thought he would."

Russell added that he thinks Walker could even play shortstop if the Pirates need to insert him there to back up Argenis Diaz, who is subbing for an injured Ronny Cedeno.

"If we needed someone to cover some innings with Neil, we'd be OK," Russell said.

Pair of Pirates back in Houston

HOUSTON -- Newly acquired catcher Chris Snyder and interim bench coach Jeff Banister definitely circled this trip to Houston on their calendars. Both played at the University of Houston and will have plenty of family watching the Pirates' series this weekend against the Astros.

Snyder grew up in Houston and can look forward to playing in Houston more often since being traded from Arizona to one of the Astros' division foes.

"It's always fun," Snyder said. "It's a good chance for me to see the people I haven't seen in a while."

Snyder said his father drove him and his son to Cougar Field to show his grandson where he used to play college baseball.

"He dug it," Snyder said. "It was cool."

Banister, who was named the Pirates' bench coach Sunday, grew up in Lamarque, Texas, and was selected by the Pirates out of the University of Houston in 1986.

Russell: Resop solid in 'pen

HOUSTON -- Reliever Chris Resop has struck out five of the last 13 batters he's faced in his last three outings. Manager John Russell said he's seen Resop's arm strength and command continue to improve.

"Each outing it seems his velocity creeps up a little more," Russell said. "He started a lot in Triple-A -- and now out of the bullpen he's starting to get in a rhythm."

Since he was claimed off waivers from Atlanta on Aug. 4, Resop has only given up one run -- with opponents hitting just .188 against him.

Russell said he's put Resop in tough situations.

"His mechanics look pretty sound," Russell said. "He's a nice arm to have down there."

Worth noting

Jose Tabata had his seven-game hitting streak come to an end after going 0-for-4 on his 22nd birthday. ... Third baseman Pedro Alvarez also had his seven-game hitting streak halted Thursday, along with his streak of at least one RBI in seven consecutive games. ... The last starter other than Paul Maholm to win at Minute Maid Park was Matt Morris in 2007.