Lopez (groin) didn't experience any setbacks following his bullpen session Friday, Kyle Williams of the Chicago Sun-Times reports.
Lopez has been dealing with a groin injury, and his last outing came against the Marlins on Aug. 23, when he struck out two batters in one scoreless inning. The 31-year-old reliever could pitch during this weekend's series against the Nationals. In 20 games since joining the Cubs in mid-June, Lopez has recorded two saves and two holds with a 0.79 ERA and 1.37 WHIP across 22.2 innings.