Police say Ball suffered head injuries from an attack by five men. Ball told police the men kicked and punched him several times.
Police say it appears as though Ball did not know his attackers and that this was an unprovoked attack.
According to Wisconsin head football coach Bret Bielema, the senior running back has been released from the hospital. Bielema says Ball is under the care and supervision of the team's medicine staff.
"My concern right now is for Montee's health and well-being," said Bielema in a statement. He added, "I do expect Montee to make a full recovery."