Barcelona and Real Madrid both face difficult starts to 2017 after drawing Athletic Bilbao and Sevilla respectively in the Copa del Rey on Friday.
Barca and Madrid eased into the round of 16 with huge wins against lower league opposition in Hercules and Cultural Leon, but they face tougher tests in the next round against two teams doing well in La Liga.
Sevilla have made an impressive start under Jorge Sampaoli and their two-legged tie against Madrid at the start of the year will be followed by a league game against Zinedine Zidane's side on Jan. 15.
The first leg of their Copa del Rey game will be at the Santiago Bernabeu, meaning Madrid will then have back-to-back trips to the Sanchez Pizjuan following their La Liga game against Granada.
Athletic are not riding as high as Sevilla in the table -- the two sides are seventh and third respectively -- but have always proven difficult opposition for Barca, who have won the Copa del Rey in the last two seasons.
Ernesto Valverde's side beat Barca in the Spanish Super Cup last season, winning 4-0 at San Mames in the first leg, and the first game of this tie will be in Bilbao at the beginning of January.
Atletico Madrid will meet Las Palmas, Real Sociedad play Villarreal and struggling Valencia take on Celta Vigo in some of the other ties.
The only two second division teams left in the competition, Alcorcon and Cordoba, who knocked out Espanyol and Malaga respectively, will play each other.
The first legs will be played on or close to Jan. 4 and the second legs will be played the following week on or around Jan. 11.
Copa del Rey round of 16 draw:
Las Palmas vs. Atletico Madrid
Alcorcon vs. Cordoba
Athletic Bilbao vs. Barcelona
Real Madrid vs. Sevilla
Real Sociedad vs. Villarreal
Deportivo La Coruna vs. Alaves
Valencia vs. Celta Vigo
Osasuna vs. Eibar