Olmos went 1-0 with a 4.50 ERA (7 earned runs in 14 innings) in six appearances with the Mariners in 2015, including two starts. He spent the majority of the year with Triple-A Tacoma where he went 1-1 with a 3.55 ERA (13 earned runs in 33 innings) in 20 games (two starts). The southpaw has a career 1-1 record with a 5.21 ERA (11 earned runs in 19 innings) in 11 major league appearances, as he was in five games with the Marlins in 2013, his only other major league stint.
He appears to have control issues. In those two brief MLB stints covering 19 innings, he's walked 11 and struck out just six. It wasn't much different in his eight minor-league seasons, either, as he has an overall 4.8 walks/nine innings ratio, although it was a bit better the last two years in Triple-A (3.0 in 2014, 3.5 in 2015). Olmos is 25 and a native of southern California. He was the Marlins' third-round pick in the 2008 draft and went to the Mariners on waivers a year ago. Maybe playing for a team whose name doesn't start with "M" will help him.
Seriously, sounds like a candidate for Bosmosis. The Cubs' 40-man roster now stands at 37.