One of two remaining major tune-ups before the French Open, the Madrid Open arrives this weekend with each of the "Big Four" having something to prove.
Djokovic wants to solidify his hold at No. 1 and enter the French Open with the year's best record on clay.
Nadal, ranked fifth, will try to recapture his pre-injury clay-court dominance. He also probably wants another shot at Djokovic heading into the French Open.
Roger Federer, secure in his legacy, seeks to prove his play is worthy of his No. 2 ranking, and that he's not ready to ride off quietly into retirement.
Meanwhile, Murray must bounce back from his thrashing at the hands of Stanislas Wawrinka in Monte Carlo.
The Madrid Open will be the first tournament since Indian Wells in which all the major players are in place. This makes it a good time to take stock of who's rising and who's falling ahead of the tournament.