Trumbo was hitting on Field 3, and beyond its left-field wall by about 20 feet is the stretch of grass where the D-backs players go through their agility drills.
On Thursday, they showed their agility by dodging home run balls off Trumbo's bat.
"There's people scattered all over," D-backs manager Kirk Gibson said with a smile. "I've got to take him off Field 3 tomorrow. That's not a good field for him to be at."
Steve Gilbert is a reporter for MLB.com. Read his blog, Inside the D-backs, and follow him on Twitter @SteveGilbertMLB. This story was not subject to the approval of Major League Baseball or its clubs.