De Los Santos, claimed off waivers from the Brewers in February, appeared in three Cactus League games, compiling a 6.75 ERA in four innings.
Now that Minor League players have reported to camp and with their games beginning on Friday, pitchers like De Los Santos will be able to get more innings on the Minor League side. In fact, of the 11 players the team has either optioned or reassigned to Minor League camp, seven are pitchers.
The Padres don't break camp in Arizona until after a game on March 28 against the Indians. They will then play two exhibition games in San Antonio against the Rangers before heading to New York for Opening Day on April 1, so there's still plenty of time to get the roster to 25.
Corey Brock is a reporter for MLB.com. Keep track of @FollowThePadres on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.