the problem with judging "trade value" in MLB (or really any sport) is that there are too many factors that we don't know how teams value. I mean things like contract length, service time, etc. A large market team may give up more for a guy like Sheets than, say, the A's would, because the money to resign Sheets wouldn't be a problem for them. So, a small-market team might conceivably value an average player with 5 years until free agency much more highly than they would a superstar with 1 year until FA. A large market team wouldn't have to worry as much about dollars and can just want the better player. all that said, I have to think that despite his slow start and questionable defensive abilities, Fielder is one of the more valuable players in MLB right now. He's still got 4 years (counting this one) till FA and his career OPS+ is identical to Mark Teixiera's, who is supposedly in line for a $200 million dollar contract this offseason. I don't think a team would offer enough to make it worthwhile to get him because in order to pry him loose, they'd have to gut their franchise. Sheets is a tougher call because of his injury history and being in the last year of his contract. If he can stay healthy till June or July, he'd probably be the best pitcher available at the deadline since Randy Johnson in 1998. The Mariners got Freddy Garcia, Carlos Guillen, and John Halama for him. Obviously Randy had more of a track record than Ben, but (barring injury) I think a package of two top prospects and a useful older guy would be reasonable to expect, depending on which teams are interested.