Morejon was recalled from the Padres' alternate training site Tuesday.
Morejon was on San Diego's taxi squad and will serve as the opener for Tuesday's contest against the Rangers. The southpaw has likely been throwing with the alternate club over the start of the season, but he presumably won't be asked to take on a heavy workload in Arlington. Morejon hasn't appeared in the majors in 2020 but posted a 10.13 ERA and 2.25 WHIP over eight major-league innings last year.