Ponson's In - Why not Rincon?

The Twins added depth to their starting rotation, or at least their candidates for the starting rotation, when they signed one-time 17-game winner Sidney Ponson on Wednesday.
Since going 17-12 with a 3.75 ERA for Baltimore in 2003, Ponson has made more headlines for weight problems and run-ins with Johnny Law. He likes to drink and then get into fights.
Still just 30, Ponson, who is the only player in ML history from Aruba, is no guarentee to make the team based on his struggles in recent years, and with the number of promising young arms the Twins possess.
Since that breakout season of '03, he has done this:

2004: 11-15, 5.30
2005: 7-11, 6.21
2006: 4-5, 6.25

Those are sub-Kyle Lohse numbers. Then again, Rick Anderson has proven to be a deft teacher, and Ponson is young enough that maybe Anderson could do something with him. And, since his last three years have been marred by off-field problems, maybe those stats are more an indication of where his head has been those three years than his arm.

I'd give Ponson a 50/50 shot of making the team.

What I'd like to see is the Twins consider Juan Rincon for the starting rotation.
I can see why they'd be hesitant, with the whole "don't fix what isn't broke" philosophy, but I really think Rincon could do it.
Carlos Silva had the same role as Rincon in Philly, and put up two fine seasons upon the Twins moving him into the rotation. Rincon has multiple pitches, and came up to the team as a starter.
He's thrown over 300 innings in nearly 300 appearances over the last four seasons, so I believe he has the durability.

The obvious question (and reason the Twins probably aren't considering this) is that their bullpen is the strength of the team, and they clearly don't want to mess with that.

If Rincon joins the rotation, then Pat Neshek and/or Jesse Crain become the top relievers, with Matt Guerrier and perhaps Scott Baker and JD Durbin in the mix.

But the Twins may have been able to find an affordable free-agent (the Indians just signed Keith Foulke) and that would've maybe made it a possibility.

With Rincon in, you'd have:
Santana
Boof
Silva
Rincon
Garza/Baker/Ponson/Durbin/Perkins

With Rincon in the pen you've got:
Santana
Boof
Silva
Garza
Baker/Ponson/Durbin/Perkins.

Either way, you're talking about a staff with some serious ifs.

The Twins are still reportedly interested in lefty Bruce Chen (0-7, 6.93 last year, but 13-10, 3.83 the year before that) and righty Ramon Ortiz (11-16, 5.57 last year, 79-76, 4.85 career).
If it's cheap, bring 'em on in. We need all the help we can get.