Milos Raonic

Nadal vs. del Potro, Carreno Busta vs. Anderson in Open SFs

If Rafael Nadal and Roger Federer had managed to meet in the U.S. Open semifinals, it would have felt as if the trophy were at stake right then and there.

As it is, the No. 1-seeded Nadal's matchup in the final four Friday against 24th-seeded Juan Martin del Potro will carry that same weight.

That's because while Nadal owns 15 Grand Slam titles, including two in New York , and del Potro won the 2009 U.S. Open, the semifinal on the other side of the bracket this time involves a pair of new faces: 12th-seeded Pablo Carreno Busta of Spain against 28th-seeded Kevin Anderson of South Africa.

Neither had ever been this far at a major. They took advantage of all of the...