Often when the baby is very young, the digestive system is not mature enough to process formula that is being used as a substitute for breast milk. This can cause constipation in the baby which can cause discomfort when passing them. Although, it is hard to say a specific time as everyone is different but one should look out for any change, dry stools or not going for 3 days.
When playing contact sports it is common for ribs to subluxate which is where they come out slightly and do not return to their normal anatomical position. Local ligament and soft tissue damage can occur.
Local pain and tenderness at the rib head which is just off to one side of the spine
Pain when taking a deep breathe in
Pain when pressure is placed over that side of the rib cage