Sanchez and VandenHurk are among six pitchers contending for three open jobs in the Marlins' rotation.
Sanchez gave up two hits, one walk, two stolen bases and one run in two innings. He threw 41 pitches, 23 for strikes.
VandenHurk allowed one hit and one walk in two scoreless innings, struck out two and threw 35 pitches.
On a cool, blustery day — 61 degrees with a 15-mph wind — Nationals starter J.D. Martin pitched two perfect innings with one strikeout. He needed only 19 pitches and threw 14 strikes.
Florida rookie Logan Morrison had a two-run triple.