For the first time Pro Football Focus is ranking the top 50 players in the game currently, and topping the inaugural list is none other than Los Angeles Rams defensive tackle Aaron Donald.

Following each season Pro Football Focus runs down its top 101 NFL players based on how they performed according to their grading system. The top 50 list, however, marks the first time they've taken a preseason approach to look at the best players heading into an NFL campaign.

Donald has fared well in PFF lists before. He ranked second overall in the top 101 players for the 2016 season, behind only the Patriots' Tom Brady. Donald also topped the list for 2015.

Donald isn't the only Ram to make PFF's top 50 list. Also recognized is free agent acquisition Andrew Whitworth, the Rams' new left tackle. Whitworth, who spent his previous 11 seasons with Cincinnati, checks in at No. 36. Below PFF explains why these players are worthy of their top 50.

1. Aaron Donald, DI, Los Angeles Rams

"With J.J. Watt injured in 2016, there has been no more consistently dominant force in the NFL over the past couple of seasons than Donald. The Rams defensive lineman has been a one-man wrecking crew inside whether against the run or as a pass-rusher. He has tallied a ridiculous 161 total pressures over the past two seasons, and 90 defensive stops, generating both pressure, and decisive pressure, at a completely different rate to any other defensive tackle."

36. Andrew Whitworth, T, Los Angeles Rams

"The only thing keeping Whitworth from being higher on this list is the fact that he is 35 years old and the inevitable knowledge that sooner or later he has to begin to display that reality on the field. Last season, Whitworth was once again one of the game's best left tackles, and he allowed just 14 total pressures all season. Whitworth has allowed 44 total pressures over the past three seasons combined, which is 23 fewer than Chris Clark allowed for Houston last year alone."