The hard-hitting Morneau, the reigning MVP in the American League, was injured Friday night when he collided at home plate with Florida Marlins catcher Miguel Olivo in the top of the eighth inning.
After the collision, Morneau stayed down for a few moments before walking to the dugout.
He later was taken to Memorial Hospital West in nearby Pembroke Pines, Fla., where the team said on its Web site that X-rays and CT scans came back normal.
The decision to keep him another night was made after Morneau saw a group of specialists, and it was determined he did not have any broken ribs.
"When he was hurting and couldn't catch his breath, yeah, we were a little concerned," said Twins Manager Ron Gardenhire.
Morneau is batting .278 with 20 home runs and 57 RBI.