The Cubs placed Lopez on the 15-day injured list Monday with a right groin strain, Sahadev Sharma of The Athletic reports.
Lopez returned from the same injury just last week, so he evidently must have suffered a setback. The injury ends what was a nice bounce-back season for Lopez, who collected a 2.89 ERA and 50:19 K:BB over 53 innings covering 52 appearances for the Mets and Cubs. He'll be a free agent this offseason.