Federer will compete for the second time this season. In March, the 39-year-old lost in the quarter-finals in Doha against frequent practice partner Daniel Evans.
The top seed will begin his tournament against Pablo Andujar or Jordan Thompson. Federer has not yet played either man. The first seeded opponent the 103-time tour-level titlist could play is fifth seed Cristian Garin, a five-time ATP Tour titlist who has lifted each of those trophies on clay.