Sure, via gravitational micro lensing. When the rogue planet or brown dwarf (which is not a planet) passes directly in front of a distant star (as viewed from Earth), the gravity of the rogue planet/brown dwarf will bend the starlight, focusing it towards Earth, causing the distant star to briefly increase in brightness. The amount of brightening depends on the mass of the body.

https://roman.gsfc.nasa.gov/exoplanets_microlensing.html