Photo

Police Commissioner William J.Bratton said he wanted “to extend a personal apology’’ to James Blake after his mistaken arrest on Wednesday.Credit Bryan R. Smith for The New York Times

Mayor Bill de Blasio and New York City’s police commissioner apologized on Thursday for the mistaken arrest of James Blake, a retired top-10 professional tennis player, who said he was slammed to the ground outside his hotel in Midtown Manhattan after being confused for a suspect in a credit card fraud investigation.

“I want to talk to him because I want to apologize to him on behalf of the City of New York,” Mr. de Blasio said in a television interview on Thursday. “This shouldn’t have happened and he shouldn’t have been treated that way.”

Earlier, the police commissioner, William J. Bratton, said he had also been trying to contact Mr. Blake, who is biracial, “to extend my apologies for the incident which he found himself involved in yesterday.”

The undercover detective who detained Mr. Blake has been stripped of his gun and badge and placed on desk duty, a tacit acknowledgment that video of the arrest raised serious questions about his actions.

Mr. Bratton, speaking at a news conference on Thursday, said he had concerns about “the inappropriateness of the amount of force that was used during the arrest.” An initial review of video evidence of the arrest, he said, led him to believe that it may have been excessive.

Mr. Bratton said the team of six undercover detectives involved in detaining Mr. Blake — all of whom were white — failed to report the incident, a breach of department practices.

The detectives who approached Mr. Blake were relying in part on an Instagram photo of someone believed to be involved in a credit card fraud ring that Mr. Bratton said looked like “the twin brother” of the former tennis star. That person turned out to have nothing to do with the scheme, police officials said, and they refused to make the photo public.

The episode provoked widespread criticism at a time when the treatment of black people by the police is under scrutiny across the country. It presented a significant challenge for Mr. Bratton and Mr. de Blasio, who was vaulted into office in part on the power of an advertisement featuring his biracial son discussing police tactics that unfairly target black people.

Mr. Blake, 35, said the episode drew attention to the kind of rough arrest tactics that he believed were all too common in New York City, but rarely came to light because they were used against vulnerable people.

“I do think most cops are doing a great job keeping us safe, but when you police with reckless abandon, you need to be held accountable,” Mr. Blake, whose mother is white and whose father was black, said in an interview on “Good Morning America” on ABC.

Mr. Blake, who was in New York to make appearances for corporate sponsors at the United States Open, was leaving the Grand Hyatt New York on East 42nd Street around noon on Wednesday when an undercover detective ran toward him.

“I was standing there doing nothing — not running, not resisting, in fact smiling,” Mr. Blake said. Then, he said, an officer “picked me up and body slammed me and put me on the ground and told me to turn over and shut my mouth, and put the cuffs on me.”

A man who sells newspapers near the entrance to Grand Central Terminal, said he watched the police rough up Mr. Blake.

“They were real aggressive, like he robbed a bank,” the man, Charlie Sanders, 55, said. “They were shoving him around.”

Mr. Sanders said he saw Mr. Blake, his hands cuffed behind his back, being handled aggressively by a half-dozen undercover officers. The officers shoved Mr. Blake face first into a large, mirrored building support beam near the Grand Hyatt, Mr. Sanders recalled. With his head wrenched to the side, Mr. Blake tried to talk.

“He told them, ‘I have my U.S. Open badge in my pocket.’” Mr. Sanders said.

Mr. Blake, who retired two years ago, said that the detective who pushed him to the ground never identified himself and did not answer his questions. He was detained for 15 minutes, Mr. Blake said, and the encounter left him with cuts and bruises.

“This happens too often,” Mr. Blake said, “and most of the time it’s not to someone like me.”

Robert K. Boyce, the chief of detectives, told reporters that the operation was part of an investigation into credit card fraud. Detectives recently learned of 16 fraudulent credit card transactions made through an Internet service provider, totaling about $18,000, and set up a controlled delivery of high-end designer shoes on Wednesday to the concierge desk of the Grand Hyatt.

The undercover detectives were working off an Instagram photo that the Internet provider gave them of someone the company thought was involved. “It is a remarkable likeness to James Blake,” Chief Boyce said.

A British man, James Short, 27, staying in New York on a student visa, met the courier to get the delivery of shoes and was arrested, the police said. Then the courier pointed to Mr. Blake from eight feet away, Chief Boyce said, identifying the former tennis star as someone who had previously bought items from him.

The detective made a “fast approach,” Mr. Bratton said, and then grabbed Mr. Blake by the arm and took him to the ground. The detective was not wearing a visible badge because he was undercover.

Soon after, another British man, Jarmaine Grey, 26, was identified as the proper suspect and arrested inside the hotel. Mr. Short and Mr. Grey were charged with grand larceny, identity theft and criminal possession of stolen property.

The detectives were supposed to have filled out a voided arrest report about the incident with Mr. Blake, police officials said, but they did not. That left Mr. Bratton to learn of the arrest through news reports later in the day. “There’s department protocols that should have been followed, and apparently were not followed,” he said.

Internal affairs investigators were looking to interview Mr. Blake, after which they planned to talk to the detective who was put on modified duty.

Police officials said the investigation would focus on what compelled the detective to use as much force as he did — whether experience in similar arrests, or an observation at the scene — and whether all the detectives involved told the truth about the encounter.

But Mr. Bratton was unequivocal in denying that Mr. Blake was racially profiled. “I don’t believe at all that race was a factor,” he said.

For Mr. Blake, a New York native who attended Harvard for two years, the arrest was the second time issues of race threw him into the public spotlight. In 2001, he was locked in a fierce match at the U.S. Open with Lleyton Hewitt, an Australian, when Mr. Hewitt appeared to make a stinging racial remark at a linesman.

He was arguing repeated foot-fault calls by one linesman. “Look at him,” Mr. Hewitt shouted, pointing to the linesman, who was black. “Look at him,” Mr. Hewitt said again, pointing to Mr. Blake. “You tell me what the similarity is.”

After losing the match, Mr. Blake handled the controversy with humility. He played down Mr. Hewitt’s remark, even though his father, sitting courtside, was infuriated and took it as racist.

On Thursday, Mr. Blake responded similarly, waving off the suggestion that he had been targeted because of his race, even though he told The Daily News a day earlier that “there’s probably a race factor involved.”

He said he decided to speak publicly only after being persuaded by his wife, who has been a publicist. “She said, you know, ‘What if this happened to me?’ and immediately I was furious,” Mr. Blake said on ABC, adding that he could not accept the idea that an officer who took “away her dignity” might be let off.

Mr. Blake became widely known on the tennis tour for his speed, his blistering forehand and his sportsmanship. He inspired feverish loyalty among a group of friends from his childhood. Known as the “J-Block”, they rooted for him at matches in Queens, most memorably when Mr. Blake and Andre Agassi thrilled the crowd in an electric five-set quarterfinal duel won by Mr. Agassi at the U.S. Open in 2005.

He reached No. 4 in the world in 2006, a stunning comeback considering the devastating setbacks he experienced two years earlier: He broke his neck in a practice and lost his father to cancer.

Law enforcement officials said Mr. Blake was released from custody on Wednesday after a retired police officer recognized him.