The definition of “sleeper” varies, but I view the following players as undervalued compared to the market. Note that some of these suggestions are geared more for deeper leagues than others.
Arizona Cardinals: Rondale Moore
The rookie’s 40 time is in the 96th percentile while his breakout age was in the 99th, and there’s potential for real volume right away for Moore. DeAndre Hopkins is approaching 30, Christian Kirk seemingly isn’t any good (No. 91 in yards per route run last year), newcomer A.J. Green looks washed (he saw the 12th-most air yards last season and finished with the 67th-most receiving yards) and the Cardinals rarely use their tight ends (and have questions at RB).