Rafael Nadal can pull within one grand slam title of Roger Federer's career record of 20 on Sunday when he faces Daniil Medvedev in the U.S. Open final at 4 p.m. ET. Oddsmakers list Nadal as a -550 favorite, with Medvedev going off as the underdog at +400.

Before you make your picks, you need to see whom Sean Calvert is backing.

Calvert is red-hot this year. In March, he took down a huge score on Dominic Thiem winning Indian Wells at 80-1, and then he called Adrian Mannarino's Libema Open title at 25-1. At Wimbledon in July, Calvert told his followers to grab 3-1 odds on Novak Djokovic facing Federer in the final, adding that Djokovic would win it all. The result: Djokovic and Federer cruised into the finals, with Djokovic winning the 4 hour, 57-minute final for his fifth Wimbledon crown. Anyone who followed Calvert's advice was handsomely rewarded.

And, Calvert absolutely owns the U.S. Open. Since 2013, $100 players following his U.S. Open bets are up nearly $7,200!

Now, Calvert has locked in strong picks on Nadal vs. Medvedev. Calvert is also betting big on total sets, who wins the opening set and how many games the first set lasts. You ABSOLUTELY need to see his picks before making any of your own.

So who wins Medvedev vs. Nadal? How long does the match last? And how many games does the first set last? ... Join SportsLine right now to see Sean Calvert's detailed U.S. Open final picks, all from the renowned tennis expert who's up more than $7,000 on his U.S. Open bets! -- Use promo code TENNIS to get your first month of SportsLine for a buck!