Vargas will start at third base and bat seventh in Sunday's game against the Reds, Andrew Golden of The Washington Post reports.
He'll be manning the hot corner for the third consecutive game and looks like he'll settle in as the Nationals' top option at the position in the wake of Jeimer Candelario being traded to the Cubs. Jake Alu appeared set to get the first chance to replace Candelario, but he's now picked up two straight starts at second base and should serve as the Nationals' primary option at the keystone after the struggling Luis Garcia was demoted to Triple-A Rochester.