The game itself went poorly, as the Blue Jays right-hander allowed three earned runs on five hits and a walk in two innings.
However, the results afterwards were the ones that stung the most.
Morrow had a setback in that outing with the same forearm soreness that had him placed on the disabled list on May 29 reappearing.
"The forearm is still bothering him," Gibbons said. "Back him off that rehab, get him re-examined, see where he's at."
Although things will be more clearly after he is re-examined, it's a big blow for both the Blue Jays and Morrow. The 28-year-old was set for another start or two in the Minor Leagues, and was on pace to be due back with the club sometime next week prior to the setback.
Evan Peaslee is an associate reporter for MLB.com.
This story was not subject to the approval of Major League Baseball or its clubs.