Buster Olney has tweeted that the Mariners may be close to acquiring 1B Casey Kotchman from the Red Sox. Prospect Insider confirms the rumor, and says that it won’t preclude the M’s from acquiring another 1B.

I doubt Kotchman is going to sit on the bench unless Boston tosses in some cash with Kotchman, as he is likely due $3-4 million in arbitration. If true, this shows that the team does not have much confidence in Mike Carp, and I suspect it’s because of his defensive shortcomings. The Mariners bench is more than full at this point, with Hall, Johnson/Bard, Langerhans, Griffey, Hannahan, Carp, and Kotchman all potential bench players. In the following weeks we should see some clarity as to how the 2010 Mariners bench will look. Nobody knows what Zduriencik has in mind these days.

Kotchman put up an .840 OPS in 2007, but has dropped to a .766 OPS in the 2 years following. He is left-handed and has a reputation as an excellent defensive 1st baseman. He will be 27 at the start of the 2010 season.

This move doesn’t make a whole lot of sense for the Mariners without cash being thrown in. However, he’s a decent back-up plan if the team doesn’t land another 1B on the free agent/trade market.

More details as they break.

Update (Jon): Alex Speier of WEEI:

The Red Sox and Mariners are close to an agreement that would send first baseman Casey Kotchman to the Mariners in exchange for a minor-league player to be named later, a major-league role player and cash, according to a major-league source. The deal is not yet finalized.

Most people figure that Bill Hall is the guy, which would be the only reason the Mariners would be sending money to the Red Sox, rather than the other way around.

I didn’t realize Kotchman was so young.  He’s been around so long that it feels like he should be in his 30s. That is… interesting.

Update (Jon): Ken Rosenthal tweets that it is indeed Hall in the deal.

Update (Jon): Geoff Baker writes that this deal won’t be official for a bit (physicals, Beltre deal, commish approval).

Update (Scott): Alex Speier of WEEI Boston writes that Seattle is expected to send along cash that they received from Milwaukee for Bill Hall.  This seems to infer that Seattle has already received $7 million or so from Milwaukee to cover Hall’s 2010 salary. It should be expected that Seattle will send most, if not all, of this money to Boston to subsequently cover Hall’s salary in Boston this upcoming season. The breaking point, as I see it, is around $5 million sent to Boston. If Seattle sends that much, Boston pays $3.4 million for Hall, which is right about the same as Kotchman would make (maybe less) in arbitration – making this deal about a straight salary swap. If Seattle sends the full amount (~$7 mill), they’re taking on about $2 million in extra salary to cover Kotchman for 2010. If they send less than $5 million, they’re saving some money by making this deal. That’s my interpretation of this, hopefully the full details will come out soon.

Update (Scott): Alex Speier also tweets that the Red Sox will come from list of Mariners prospects who the Red Sox will evaluate in spring training. Translation – it’s most likely not going to be anybody significant.

Update (Jon): Prospect Insider is reporting that the PTBNL is a catcher not named Baron or Coleman.  With those guys off the table, the chances of you ever missing this guy is small, though PI mentions Hassiel Jimenez as the only possible prospect that could be available.  I totally whiffed on him for the catcher’s prospect report.