Steele will be recalled from the alternate training site before Sunday's game against the Pirates, Patrick Mooney of The Athletic reports.
The 25-year-old struggled in 11 starts (38.2 innings) at Double-A Tennessee with a 5.59 ERA and 1.70 WHIP last season, but he'll now join the Cubs to potentially make his major-league debut. Steele is likely to be utilized in a low-leverage role.