Mid-May callups are an intriguing lot, and the opportunities for older minor leaguers to get their first run as everyday options seem to peak as most teams wait until early or mid June to start their prospects' arbitration clocks. In some instances, an organization will give a mid-level prospect his first exposure to the big leagues, and that player will prove capable of replacing a regular while holding onto the job all year.
In other cases, teams spin the tires for a couple weeks as replacements falter, and the placeholders ultimately end up getting move back to the bench (or the minors). For fantasy owners, it's important to consider the things that could go right when evaluating FAAB and waiver-wire targets this time of year, as prices should begin to drop in leagues that use free agent budgets and commitments to players are much less firm.
Here's a look at 10 depth-chart situations around the league that have recently led to a shift in playing time distribution.