The woman alleged the incident occurred at 3:50 a.m. ET Sunday outside the Marquee, a nightclub in Manhattan's Chelsea neighborhood, police said. Police are investigating a complaint the woman filed Monday evening. Marshall has not been charged.
In a statement, Bears general manager Phil Emery said the team was aware of the alleged incident when it obtained Marshall from the Miami Dolphins on Tuesday.
"Both the Bears and Dolphins were aware of what occurred over the weekend. We decided to move forward with the trade. We have high expectations for Brandon as a Bear," Emery said.
A source, however, told ESPN NFL Insider Adam Schefter that although the Bears knew there was an incident involving Marshall, the team didn't know the details or that he was being investigated by police.
Marshall's attorney, Harvey Steinberg, said in a statement early Wednesday morning that Marshall and his friends were not involved in the melee.
"Brandon Marshall was the keynote speaker at a charitable event in New York. After the event was over he, his wife and close friends attended a function at a local club," the statement said. "While at the function a fight broke out NOT involving Mr. Marshall or his friends."
Marshall allegedly got into an argument with a group of friends celebrating a birthday at the club, the New York Post reported. According to the Post, Christin Myles, the woman celebrating a birthday, briefly left an upper floor of the club. Upon returning, the paper reported, Myles was told to wait because Marshall allegedly was involved in a fight with an unnamed football player and both players were being removed from the club.
Myles eventually met with her friends outside, the Post said, and found the 6-foot-4 Marshall and the unnamed player arguing with her group. Marshall then allegedly punched Myles in the left eye, leaving her with a black eye, according to the Post. It wasn't clear if Marshall intentionally struck Myles or if he meant to hit one of her friends, according to the report.
Steinberg said that while Marshall and his wife were attempting to leave the club, Marshall's wife was hit in the face with a bottle and suffered "serious" injuries that required hospitalization.
Steinberg said Marshall would cooperate with the investigation.
Tuesday's trade reunites quarterback Jay Cutler with Marshall. The two played together for three seasons with the Broncos. In an interview Wednesday with the "Waddle and Silvy Show" on ESPN 1000, Cutler said he has a "good idea" what happened in the incident.
"Obviously I wasn't there, but like I said, it's all going to play out," Cutler said. "I'm super excited to get him. It's unfortunate that this came out when it did. We don't want to paint a bad picture of Brandon Marshall. Does he have a record of stuff in the past? Absolutely, but I know him as a person, not only as a player, and he truly is a good guy. We got a good teammate and we got a heck of a player."
Marshall previously was involved in off-field issues as a member of the Broncos. He wore out his welcome in Denver partly because of a long legal record and conflicts with former Broncos coach Josh McDaniels.
Marshall was involved in a New Year's Eve altercation that preceded the 2007 drive-by slaying of Broncos teammate Darrent Williams.
In testimony during the trial of Willie Clark, the man who was found guilty of murder in Williams' death, Marshall said he "probably escalated the situation" at a Denver club where he, Williams and other Broncos teammates were celebrating before Williams was fatally shot while riding in a limousine.
The NFL also suspended Marshall three games in 2008 for violating the league's personal conduct policy; that suspension was reduced to one game that August.
Marshall has had numerous runs-in with the law since entering the NFL in 2006. His history of arrests also includes disorderly conduct, drunken driving and a number of incidents of alleged domestic violence.
Marshall's wife was arrested a little less than a year ago after he was stabbed in the abdomen with a kitchen knife during a domestic dispute. Charges were later dropped.
If the NFL investigates this incident and finds Marshall violated the league's personal conduct policy, he could be subject to discipline. Under the player conduct policy, NFL commissioner Roger Goodell has the power to suspend players for repeated bad behavior off the field.
Information from ESPN NFL Insider Adam Schefter and The Associated Press contributed to this report.