Lopez will start Sunday's game against the Nationals, Jason Burke of Roundtable.io reports.
A path was cleared for Lopez to re-enter the Athletics' rotation when Aaron Civale was designated for assignment Wednesday. Lopez has made two relief appearances since being recalled from Triple-A Las Vegas last week, allowing four runs with a 5:1 K:BB over 4.2 innings. All told, the southpaw has logged an ugly 6.83 ERA, 1.79 WHIP and 43:34 K:BB over 55.1 innings in the majors this season.