The boy was taken to Stroger Hospital in good condition.
Contreras has stayed on the field the last two games against the Reds, despite rolling his ankle in the ‘‘Field of Dreams’’ game.
The Cubs acquired the utility man from the Dodgers for veteran reliever Chris Martin.
One thing is sure, the Soldier Field turf needs work.
Emergency crews responded to a call of people in the water about 5 p.m. in the no-wake slip often referred to as “the Playpen,” Chicago fire officials said.