I also never thought to do that either... a large backloaded team option year... Which kind of surprises me... while I usually have pretty good self control about exploiting the AI, I do like finding out exactly how far they can be pushed.
About as far as I've weaseled is to front load a contract on occasion... There was a 36 year old fragile reliever that was insisting on three years... and I wanted nothing to do with that. Finally, I gave him his three years but with $7m in year one and $2m in each of the next two. Figured if I had to cut him outright down the road most of the money was spent in the first year... and if I decided to try to trade him the $2m figure would look better to the AI. In the end, he actually gave me two solid years bouncing between middle relief and setup man and then retired prior to year three.