I know everyone would like to see the Royals acquire Giancarlo Stanton, or Chase Utley before 2014, but that's not going to happen. Regardless, the Royals could improve up the middle pretty drastically, for 2014 and years to come, if they look at it from a more realistic point of view.
Kolten Wong is a top 5 prospect in the Cardinals deep and rich farm system, and a top 100 prospect overall (BP-90, BA-84). He is 22 years old, and performing quite well in AAA-Memphis. Normally, Wong would not be the type of prospect an organization would be all to willing to let go, but the Cardinals do have depth, and All-Star 2B already in Matt Carpenter.
The Cardinals rotation is good, but could get better, especially in light of recent struggles from Lance Lynn and Shelby Miller. Joe Kelley has performed decently at the back end of the rotation, but it is no secret that the Cardinals would prefer that he work out of the bullpen. Add a guy like Ervin Santana to that mix, especially with the year he is having, a the Cardinals rotation would be surely among the league best, and one would think they could build a little breathing room atop the NL Central.
Louis Coleman and John Jay could be switched out for different pieces, but Ervin Santana and Kolten Wong would be the base for this trade. I would say Santana for Wong straight up, but I don't think the Cardinals would want to give up a prospect like Wong for a half year of anybody. Coleman would give them something a little more permanent, and cost effective, and I know they probably would like to move Jay to make room for Oscar Taveras. You may not think Jay would be an upgrade over Cain or Lough, but he is posting a .331 OBP in a down year, and still has a career OBP over .350. Plus John Jay would give us some much needed, Major League ready depth in the outfield.
I'm not sure this particular trade plan is something the Cardinals would go for, but I definitely think that there could be a mutually beneficial Santana-Wong trade among these two teams, and I for one would like to see Dayton explore this possibility.