Derrick Williams, 24, was charged with attempted murder, armed robbery, obstruction and another count of robbery, police said.
Williams and an alleged accomplice tried to rob a 70-year-old man in an O'Hare-bound train car on the Blue Line as it approached the LaSalle Street station about 12:30 a.m., police said.
One man accused the victim of taking his cellphone, and when the victim began to walk away, the men pushed him to the ground, police said.
One of the men kicked the victim in the face when he tried to fight back, and one cut the victim's pants and took his wallet.
Williams' accomplice accidentally stabbed him when trying to stab the victim, and that man fled the scene with an unknown amount of cash when the train stopped at LaSalle, police said.
Williams tried to flee into another train car but was detained by police. He was arrested and taken to Northwestern Memorial Hospital, where police said he became combative and spat at officers.
The robbery victim was taken to Northwestern Hospital as well with injuries to his face.
Williams was scheduled to appear in court again Monday.