CINCINNATI -- Aroldis Chapman was scratched from his planned Arizona Fall League start on Monday because of a sore left shoulder.
The Reds' left-hander made two relief appearances for the Phoenix Desert Dogs last week in the AFL.
"He had a little inflammation in his shoulder," said Reds general manager Walt Jocketty. "It was probably from trying to do too much, too soon. He didn't do a lot before going down there."
Chapman, who threw 2 2/3 innings of relief and gave up one hit and one run, was pitching in the AFL to begin a transition towards becoming a starter next season for Cincinnati. He was expected to start some games and stretch out his arm in Puerto Rican winter ball next month.
The immediate plan for Chapman remains unclear.
"We'll try and determine that," Jocketty said. "We'll have a better idea the next day or two, and see how he's responded to the medication."
In other injury news, catching prospect Yasmani Grandal's AFL season is over because of a sore middle finger on his left hand.
"We sent him home," Jocketty said. "He couldn't really do anything. The more he swung the bat, the more it got swollen. It's nothing serious. He just needs to let it heal over time."
Grandal, the Reds' first-round Draft pick in 2010, played only three games in the AFL before a freak injury.
"I was just catching a bullpen and I didn't notice the guy throwing," Grandal said last week. "I was kind of looking down. It hit me on the side of my finger. They said it would take about three weeks to start feeling better in the hand."
Mark Sheldon is a reporter for MLB.com. Read his blog, Mark My Word, and follow him on Twitter @m_sheldon. This story was not subject to the approval of Major League Baseball or its clubs.