Last week came word the Mets had traded veteran backup catcher Vance Wilson 3 to Detroit for minor league infielder Anderson Hernandez;signed veteran backup infielder Miguel Cairo; and signed lefthanded reliever Dae-Sung Koo. That Wilson was the Met to go was surprising but, in our estimation, the right choice to make seeing as Jason Phillips 23 is younger, a better receiver and possesses more of an upside, notwithstanding his lousy sophomore year. One thing certain about Cairo is that you won’t see him in his customary No. 41: That’s unavailable. Aquiring Koo was a coup in that newspapers hinted he, like Beltran, was simply assumed to be a future Yankee. Heh. Said to have a sneaky arm that will trouble lefthanded hitters, Koo wore No. 15 with Orix of the Japan Pacific League — that will belong to Beltran for awhile.