WATCH: Zverev, Thiem meet FC Barcelona

Alexander Zverev and Dominic Thiem are known supporters of Borussia Dortmund and Chelsea F.C., respectively, but this was an opportunity no soccer fan would want to pass up.

Ahead of the Barcelona Open, Zverev and Thiem got to visit the practice grounds of FC Barcelona, the reigning champions of Spain's La Liga.

"This is one of the best clubs in the world," Zverev said, "To see how they function, to see how everything is here—and the practice grounds as well—is amazing."

In addition to seeing the facilities, the ATP stars got to meet some of Barcelona's best players, including Gerard Pique, who also serves as president of Kosmos, the group investing in the revamped Davis Cup.

Zverev, the No. 2 seed in Barcelona, made a second-round exit on Tuesday, dropping a match point before falling in a third-set tiebreak to Nicolas Jarry.

Thiem, in his second-round match, defeated Diego Schwartzman, 6-3, 6-3. His next opponent will be No. 57 Jaume Munar.