2/16 UPDATE:
The Cubs have signed RHRP Shae Simmons to a major league contract (not a minor league contract as was first reported two days ago -- see 2/14 UPDATE below) and it has been filed with the MLB office. So Simmons has been added to the Cubs MLB Reserve List (40-man roster), and LHSP Drew Smyly (July 2017 TJS) has been placed on the Cubs MLB 60-day DL to make room for Simmons on the 40.
The Cubs have signed 27-year old RHRP Shae Simmons to a 2018 minor league contract and he has been assigned to AAA Iowa.
2/14 UPDATE: