The witnesses said the man seemed dizzy when he lost his footing at noon Wednesday at the East Broadway station and fell to the tracks just as an F train headed for the Brooklyn borough was pulling into the facility, the New York Daily News reported Friday.
The commuters said the man was pinned under the train until he was freed by emergency workers.
"He looked messed up, but he was talking," witness Karim Carter, 34, said.
"He was disoriented. He looked like he just got dizzy and fell on the tracks ... facing down," Carter said.
Police said the man, who was not carrying identification, was taken to Bellevue Hospital in serious condition. The nature of his injuries was not released by authorities.
The incident came after transport worker Sabrina Scott, 39, was knocked to the tracks at the same station by a man Feb. 4. She was pulled from the tracks by a witness before the train pulled in and was not injured.