Despite there being significantly more turnover on MLB rosters today compared to previous generations, it's impossible to please everybody. Each team has a disgruntled player who passionately seeks a trade.
Veterans, of course, make winning a high priority after cashing in on a sizable guaranteed contract. Guys like Ricky Nolasco (Miami Marlins) and Alfonso Soriano (Chicago Cubs) have vocally expressed their desires to move from doormats to contenders.
However, in most cases, frustrated individuals have not accomplished enough at the major league level to announce their intentions publicly. They would be widely criticized for doing so. Instead, we are left to make assumptions based on their on-field conduct and seemingly unfair share of playing time.
All of the following players have reason to believe that the grass is greener for them elsewhere.