The upside of the signing would be that Steve's found a brief fountain of youth that will revitalize his power and he becomes a solid pinch hitter and power alternative to Taveras every fifth or sixth day.  Basically, a limited exposure .270/.340/.440 type, which would make for a nice caddy.

Downside is that he's dropped in the post spring cut-down.

Projection systems, like PECOTA, don't see anything left in the tank, and would need a flukish production boost to be valuable.  To that degree, it's still unlikely that he could outproduce the competition for the backup role.  However, the skill set could benefit Finley in the race, assuming he hits above the expected.  He's got more power and patience than Sullivan, and more defensive ability than Gomez.  A healthy and relatively effective Finley can add the value that Taveras cannot, namely power and, say it with me, "veteran leadership."  While I've outlined the differences between Sullivan and Taveras before, they are still fairly similar players when it comes to surface values.  However, at this stage of Finley's career, he might not be much more different than the forgotten man, Jeff Salazar, who's had some pop in his past, and may be Finley's equal in the department now.

This move cannot be made for starting competition, because that's more than foolish.  Giving more than 200 ABs to a 42 year old whose last good year in a starters role was three years ago, in a "bounceback" season.  This team needs a Taveras breakout at age 26 more than it needs a Finley one at 42.

Overall, this should just be a roll of the weighted dice.  The rare chance Finley bucks the system will make him worth the try, but at some point this team can't dilute the centerfield pool by giving away too many at bats.