BARCELONA: Rafael Nadal will miss Spain''s Davis Cup final against Argentina because of a knee injury.The top-ranked Nadal said he was still struggling with tendonitis in his right knee following a week of treatment.Nadal''s absence deals a big blow to Spain''s bid for a third Davis Cup title since 2000. Spain captain Emilio Sanchez Vicario has until Tuesday to name his team.Spain plays Argentina on indoor hard court at Mar del Plata from Nov. 21-23.