Morejon was called up from Double-A Amarillo on Sunday.
Morejon is set to make his major-league debut as the official starter Sunday against the Cubs. However, reports prior to his callup indicate that he'll be used as an opener. It would be surprising to see him work deep into the game, as he has pitched more than two innings only once since mid-April. Cal Quantrill is expected to work as the primary pitcher after Morejon bows out.