The Cubs have had three off days since April 8, and thus did not need a fifth starter through that time span.
Now, they are in a stretch of 16 straight days playing baseball until their next off day, which will happen May 6 in between series against the Dodgers and Pirates at Wrigley Field.
Thus they will need a full complement of five rotation starters through that period, and to fill out the rotation, Adbert Alzolay was recalled from the Cubs’ alternate site in South Bend to start Saturday afternoon’s game against the Brewers.