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09/02/11 11:07 PM ET

Additions bolster D-backs' bench, bullpen

SAN FRANCISCO -- The D-backs added five players Thursday when the rosters expanded and could bring up even more once the playoff runs of Double-A Mobile and Triple-A Reno end.

Infielder Geoff Blum was reinstated from the disabled list along with left-hander Alberto Castillo.

Meanwhile, catcher Robby Hammock along with pitchers Sam Demel and Ryan Cook were promoted from Triple-A Reno.

"He's a switch-hitter, can play anywhere in the infield," D-backs manager Kirk Gibson said of Blum. "Robby Hammock, third catcher, he had the most experience and he's also very versatile. He can play anywhere, really, on the whole diamond."

With rosters expanding in September, Gibson did not want to run short on pitching in case the team finds itself in an extra-inning game.

"There's a lot more matching up that's going to go on in this last month, so we have three lefties now as well as the additional right-handers," Gibson said.

Blum returns, hopes to contribute to D-backs

SAN FRANCISCO -- Geoff Blum tries to keep a sense of humor about it.

"First September callup, so I'm pretty excited about it," joked the D-backs veteran infielder, who was activated from the disabled list Friday. "Hopefully I've got that target off my back and sacrificed the right number of chickens and things like that. Hopefully I'm well rested for a big push here down to the end."

Signed to a two-year deal during the offseason, Blum was expected to see significant playing time this year, but a knee injury during the spring that required surgery kept him out for the first 92 games of the season.

Blum appeared in seven games before fracturing his right pinkie finger and missing the next 35 games.

"This physically has been the worst year of my career," Blum said. "It's been tough to be patient with things that are out of my control."

D-backs manager Kirk Gibson said he plans to use Blum mainly as a reserve but did not rule out the occasional start.

Hammock shocked to return to Majors

SAN FRANCISCO -- Robby Hammock always had hope that he would return to the big leagues at some point.

But the D-backs catcher thought it would be as a coach or manager.

Instead, the man who caught Randy Johnson's perfect game in 2004 found out Wednesday night that he was headed from Triple-A Reno to the big leagues.

"I was like, me?" Hammock said. "It caught me so off guard. I've seen crazier things happen in the game, but that was the last thing on my mind at the time. I was numb for a good hour trying to process everything. Obviously it was not something that was based on performance, it just has to do more with history and experience and the team here being in a playoff race. Who knows, I might not even get an at-bat this whole month."

Hammock gives D-backs manager Kirk Gibson the flexibility of having a third catcher as well as someone who can play almost anywhere on the field, including most infield positions as well as the outfield if need be.

"It was pretty much the consensus that he was the guy because of all his experience," Gibson said. "He's very smart and he brings a lot to the table for us."

Hammock, 34, signed a Minor League deal with the D-backs during the offseason with the idea that he would spend the year at Reno making the transition from player to coach.

"I love playing, I love the game, I love playing the game," he said. "That's why I want to coach or manage when I'm done, but my body felt great and I just felt like I could still play. I wasn't going to try and play to prove anything, just to enjoy the game."

Hammock last played in the big leagues in 2008 when he appeared in 18 games for the D-backs.

In 2009 he spent the season with the Orioles' Triple-A affiliate, and last year he appeared in 22 games for the Yankees' Triple-A team.

In 120 plate appearances for Reno this year, he hit .257 with a .353 on-base percentage and a .495 slugging percentage.

D-backs mulling callups for Bauer, Parker

SAN FRANCISCO -- The D-backs are still considering calling up top pitching prospects Trevor Bauer and Jarrod Parker, GM Kevin Towers said Friday.

Bauer was the team's No. 1 pick (third overall) in the 2011 First-Year Player Draft while Parker was its top selection (ninth overall) in the 2007 Draft.

"[Bauer's] name was discussed as well as Parker," Towers said. "We'll just have to wait and see how things go up here, so I guess there's a chance still, yeah."

The D-backs are trying to hold off on any more September promotions until the playoff runs of Double-A Mobile (where both Parker and Bauer are pitching) and Triple-A Reno are over.

If either pitcher were to be called up, they would likely see only minimal action in relief, according to Towers.

"I don't even know how much work they would get," Towers said. "It's more just two guys that we think have a chance maybe make our club next year and just the experience of being in postseason play the pace of the game, what to expect. That experience I think would be valuable as well."

Bauer experienced his first rough outing as a pro Tuesday when he allowed 10 runs on eight hits while walking three in just 1 2/3 innings. D-backs pro scout Mike Piatnik was in attendance for that game so Towers got a first-hand account of what happened.

"Getting too much of the plate," Towers said. "One of those times where the hitters had his number. It wasn't that he was really wild he was just not hitting his spots. I'm sure it was a little bit of a wake up for him, probably he's never had an outing like that his entire life. I'm sure he'll be better because of it the next time he goes out there."

Steve Gilbert is a reporter for MLB.com. Follow him on Twitter @dbackswriter. This story was not subject to the approval of Major League Baseball or its clubs.