The Mariners are about to announce that they've acquired Bill Hall from the Milwaukee Brewers. We expect an announcement in 15 minutes (UPDATE: 3:26 p.m. -- It's official and Erik Bedard has been transfered to the 60-day DL to clear a roster spot)..

No official word yet on who is going back the other way, though I just got it confirmed that it's minor league pitcher Ruben Flores.

Hall will be put on the major league roster and will join the team here in Detroit.

The slumping third baseman/outfielder was designated for assignment by the Brewers a week ago and the team had until Friday to trade, outright to the minors or release him.

So, why are the Mariners making this move?

Added depth for one.

Adrian Beltre is out for the next 10 days with that injured testicle. We were told this afternoon by manager Don Wakamatsu that the swelling has yet to go down for Beltre and that he won't be joining the team on this road trip.

Not only that, but the Mariners need an option other than Jack Hannahan at third.

Hannahan's numbers as an everyday player have not been good since Beltre was hurt. The last seven days have seen Hannahan produce an on-base-plus-slugging percentage (OPS) of .631. That's good for a backup infielder, not for a third baseman. Yes, Hannahan has an on-base percentage of .370 during that time.

But there's a reason this team has scored only two three runs or fewer per game most of the last week. You need some power.

Hall gets here tomorrow. The team will have to clear a 40-man roster spot for him, which it can do by transferring Erik Bedard from the 15-day DL to the 60-day DL.

As for the 25-man roster spot, there are multiple ways the team can go.

It can option Hannahan to Class AAA. Or, it can ship out Josh Wilson and make Hannahan the temporary shortstop until Jack Wilson is ready to return. That's no certainty for this weekend yet. Wakamatsu told us the goal is to get Jack Wilson into at least one of the games in Cleveland. But that's not certain yet, He could still be out until next week against the A's back in Seattle.

Yes, Hall does play the outfield and Ryan Langerhans has not exactly been lighting things up offensively. But Hall is a natural infielder and has put up above-average defensive numbers for several seasons at third. Hall's exposure to the outfield has been minimal, while Langerhans is a good defnesive player.