What happened: The Chicago Cubs announced Monday they have claimed right-handed reliever Eduarniel Núñez off waivers from the Baltimore Orioles. The transaction comes as the club awaits MRI results for starter Jameson Taillon, who exited Sunday's game against the Giants with a strained left hamstring.

Why it matters: The potential loss of Taillon further thins a rotation already missing Justin Steele and Cade Horton. The Chicago Cubs are currently fighting to maintain a winning record following a dismal 7-20 stretch that has left them 7.5 games behind Milwaukee in the NL Central.

What to watch: The Cubs travel to Colorado to open a three-game series against the Rockies on Tuesday. Right-hander Javier Assad is expected to remain in the rotation if Taillon requires an Injured List stint.