Which MLB players are in danger of big downturns in 2019?

Jon Lester will have to rear back and beat Father Time and declining performance in his age-35 season. Rick Scuteri/USA Today Sports

Baseball's best players can make the game look easy at times, but maintaining high-level performance is hardly automatic. Even MVPs and Cy Young winners are vulnerable to the gravitational forces of the profession, namely injuries, aging, slumps and regression. Sometimes it can take more than a single season for luck -- good or bad -- or sheer randomness to even out, but when it does, those snazzy stat lines can take quite a hit.

As we look toward the 2019 season, here are five players -- all of them coming off solid to spectacular 2018 performances -- whose chances for drop-offs stand out for one reason or another. For some, key indicators from last year suggest their good fortune might run out. For others, our projection systems (at FanGraphs, we use a blend of Steamer and ZiPS for our depth charts projections) have a particularly pessimistic view, even if advancing age isn't a major factor. The players below are by no means the only ones expected to slip from 2018 to 2019, but they make for an interesting cross section of the ways in which decline can show itself. Of course, it's always worth remembering that projections are not destiny, and that the best players tend to be the ones who consistently beat the odds of falling off.