Diamondbacks manager Kirk Gibson confirmed Thursday that Geoff Blum will undergo left knee surgery.

Blum hoped to begin a rehab assignment this week, but continued to have soreness in the knee. He'll likely miss somewhere around 4-6 weeks, though we'll have a more clear timetable for his return once he undergoes the procedure.

Geoff Blum took ground balls Friday for the first time since dealing with swelling in his right knee starting in mid-March.

He'll test the knee out by running Saturday. "I don't think I'm in any rush to force the issue," he said. "We'll just kind of let my knee talk." Blum should be ready to play relatively soon if the knee feels good following Saturday's workout.

Diamondbacks placed INF Geoff Blum on the 15-day disabled list, retroactive to March 22, with a swollen right knee.

Blum was given an injection in his knee last week, but just didn't have enough time to get ready for Opening Day. There's a chance he could be ready to return for the Diamondbacks' home opener next Friday.

Geoff Blum (knee) is expected to open the regular season on the 15-day disabled list.

Blum began complaining of swelling in his right knee last week and things haven't gotten any better since for the 37-year-old. The injury will open things up for Ryan Roberts to make the Diamondbacks' Opening Day roster.

Diamondbacks signed INF Geoff Blum to a two-year contract.

It's now official. Blum hit just .267/.321/.356 for the Astros this season, doesn't play godd infield defense any longer and turns 38 before the start of the 2011 season, but the D'Backs are going to bring him in anyway on a two-year pact. He'll serve as a utility infielder down in the desert.

MLB.com's Steve Gilbert reports that Geoff Blum's new contract with the Diamondbacks will be for two years, not one.

An odd deal, to say the least. Blum will turn 38 at the start of the 2011 season and posted a poor .267/.321/.356 batting line this year with just two home runs in 202 at-bats. He played all around the infield and will do the same in Arizona, but his range is poor and will only get worse as he gets closer to age 40. New D'Backs GM Kevin Towers is not off to a good start.

Steve Gilbert of MLB.com reports that the Diamondbacks are nearing agreement on a one-year deal with infielder Geoff Blum.

The Astros declined Blum's $1.65 million mutual option at the end of the 2010 regular season and it would be a shock if he landed more than that in Arizona. He posted a .267/.321/.356 batting line, two home runs and 22 RBI in 202 at-bats this season while playing a variety of different positions.

The Astros have declined their portion of the $1.65 million mutual option on infielder Geoff Blum.

The infielder doesn't have any power and only walks at about an average rate - his .267/.321/.356 was pretty typical for him - but now it also looks like his defense is slipping at 37 years old, which might make it hard for him to catch on with any team next year. Blum was a little broken up upon hearing the news, but that's baseball.

Geoff Blum (neck) will not be available for Friday's game against the Mets.

Blum had some sort of reaction to an injection given to remedy his sore neck. He is expected to rejoin the team on Saturday, however.

Geoff Blum is headed back to Houston to have his neck examined.

Blum has been dealing with soreness in the neck since the weekend and can't seem to shake it. The Astros' medical staff should be able to provide him with some answers. For now, the veteran is day-to-day.

Geoff Blum returned to action on Tuesday August 24.

Astros manager Brad Mills hopes Geoff Blum (neck) will be able to pinch-hit Monday night.

Blum was unavailable for Sunday's finale against the Mets due to a sore neck.

Geoff Blum has been dealing with a knee injury lately.

It's not clear when he suffered the injury, but it doesn't appear to be much of an issue, as he played in three straight games before sitting out last night. Blum has been getting some playing time at second base lately, but with Tommy Manzella back, he'll now have to fight with Angel Sanchez, in addition to Jeff Keppinger, for playing time.

According to Jon Paul Morosi of FOXSports.com, the Cardinals have interest in Geoff Blum.

Sources tell Morosi that it's nothing serious at the moment, however. Blum, 37, is batting .268/.326/.348 with one home run and 17 RBI in 164 at-bats with the Astros this season. Buster Olney of ESPN.com reported that the veteran utility man cleared waivers earlier this week.

Buster Olney of ESPN.com reports that Geoff Blum has cleared waivers.

Blum, 37, is batting .266/.327/.325 with zero homers and 16 RBI in 154 at-bats this season and recently returned from elbow surgery. He's another possibility should the Braves or Cardinals seek insurance at third base, writes Olney.

Geoff Blum (elbow) has played two rehab games at Double-A Corpus Christi and is expected to rejoin the Astros this week.

Blum underwent surgery on his right elbow in early July and has accomplished a speedy and improbable recovery. The 37-year-old should begin seeing regular time on the Houston infield once he is activated, but with a .241/.311/.307 batting line over 137 at-bats, he is not a fantasy guy.

Geoff Blum took batting practice Monday for the first time since undergoing right elbow surgery earlier this month.

Blum took 15 swings left-handed and about seven right-handed. He originally hoped to return by the end of the month, but we're probably looking at early August as a best-case scenario at this point.

Geoff Blum had the surgical stitches removed from his right elbow over the weekend.

Blum underwent surgery to remove loose bodies from his elbow earlier this month. He will begin working on his range of motion before resuming baseball activities. The veteran infielder is likely to return sometime in early August.

Geoff Blum underwent surgery to remove loose bodies from his right elbow Wednesday morning.

Blum is expected to be sidelined for two to four weeks. The 37-year-old infielder is batting .241/.311/.307 with zero homers and 14 RBI in 137 at-bats this season.

Geoff Blum will have bone chips removed from his right elbow Wednesday.

Blum felt a "pop" in his elbow while getting dressed last week. Upon having the injury looked at by doctors, it was discovered that he had loose bodies in his right elbow. There's no clear timetable for his return at this time.