There's always veteran guys with ERA's around league average that get moved. Especially those with a name like Shields carries. I realize he's fallen from his TB/KC days, but that whole name/experience thing does seem to get nibbles on pitchers past their prime. I mean, we moved Miguel Gonzalez last season. The Cubs traded for Hamels and his 4.72 ERA. Liriano was rather pitiful last season as a starter - Houston got him and stuck him in the bullpen... etc...
I mean, he's going to pitch 200 innings with respectable numbers. That has value on it's own. There's contenders who can use that at the back end, IMO. Teams have dealt for worse.