There are no obvious signs or symptoms before the trauma takes place for commotio cordis. Typically once the athlete is hit, typically from a ball, the collapse occurs. There may be a brief regain of consciousness to where they may even get up and throw the ball. Or have an episode of crying before they go unconscious again. In general, there's no predisposing signs or symptoms of this occurring. Often the impact to the chest does not appear to be significant to bystanders. So, unfortunately, often it may appear they just had the wind knocked out of them initially until it's recognized that there's a much more serious event taking place.
