You'll see player durability marked in a column headed with a heart icon on our Sortable Rankings and Projections pages, with each player receiving a letter grade.
Copied from the rankings key, at the bottom of the linked page above:
"♥ = Player's Durability graded A to E. Player Rankings are key, but you also want to keep your eye out on other factors while drafting. Example: you might not always want to draft the highest ranked RB if doing so would give you a backfield with two E-Grade Durability RBs. In some cases, taking a slightly lower ranked RB with proven durability is the wise move."