Ex-Twins watch: Johan Santana

If you have the same grasp of detail of the structure of the shoulder that I do, knowing that Johan Santana needs surgery to repair the torn anterior capsule of his left shoulder doesn't tell you very much.

Johan Santana works in what proved to be
 his final game of the 2010 season

But the prognosis of almost half a year before he can being throwing — much less pitch — should tell us how potentially serious this surgery is.

Santana's season is over — another season in which he clearly outpitched his support. His 11-9 record belies the 2.98 ERA, 10th best in the National League. He may not be, as he was in his heyday with the Twins, the best pitcher in baseball, but he's still very good.

Or he has been very good, What he will be after this surgery is unknowable. Santana himself is optimistic, but the track record of the procedure on pitchers isn't particularly promising. Chien-Ming Wang and Kelvin Escobar, for example, have not bounced back well.

Santana, 31, is has another three years left on his contract — three years at more than $20 million per season, a hefty commitment even for a healthy pitcher. This is his third season with the Mets, and this will be his third significant surgery.

Setting aside the return on the Santana trade, it's quite possible the trade will prove worthwhile for the Twins because it meant they're not paying him $20 million plus to break down.