Barcelona striker Luis Suarez says he has talked to specialists about his behaviour and insists there will be no further biting incidents.
Suarez is serving a four-month ban for biting Italy's Giorgio Chiellini at the World Cup - his third biting offence.
"I say to fans, don't worry, because I won't do that anymore," he promised.
"I spoke to my psychologist and he said I had to face it and say sorry. I did - now I would rather focus on the present, which is Barcelona."
|Luis Suarez controversies|
|June 2014: Banned for four months from any football-related activity, plus nine international matches, for biting Italy defender Giorgio Chiellini|
|April 2013: Apologises for biting Chelsea defender Branislav Ivanovic and receives a 10-game ban|
|Dec 2011: Given eight-match suspension and fined £40,000 for racially abusing Manchester United's Patrice Evra|
|Nov 2010: Given seven-match ban for biting PSV Eindhoven's Otman Bakkal on the shoulder while playing for Ajax|
The 27-year-old Uruguay striker, who said he was "really depressed" after the incident in Brazil, launched an appeal with the Court of Arbitration for Sport against the ban.
Following the verdict, the former Liverpool striker is still banned from playing in competitive fixtures until late October and must also serve the remaining eight games of his nine-match international ban.
But Suarez is no longer excluded from "all football-related activities", which allowed him to make his Barcelona debut as a 75th-minute substitute in the 6-0 friendly victory over Mexican side Club Leon on Monday.
Addressing a media conference on Tuesday, he said of his behavioural issues: "I am speaking to professionals - the right professionals. But it is a private matter and I don't want to comment further on that."
Suarez spent three years with Liverpool, during which he was banned for eight matches for racially abusing Manchester United's Patrice Evra and suspended for a further 10 matches for biting Branislav Ivanovic of Chelsea.
Last month, he joined Barcelona for a reported fee of £75m but the Catalan club's vice president Jordi Mestre said on Tuesday the actual amount was significantly less.
"Negotiations started before the World Cup and we worked hard to come to a final figure of £65m. We were originally quoted over €90m (£72m).
"He had much better offers than ours financially but he wanted to come to Barcelona. He made a great effort - financially and personally - to be here."
Suarez admitted he feared for his career after the incident with Chiellini in Uruguay's 1-0 win in Natal on 24 June.
"Of course I was concerned - not just about the transfer to Barcelona but more for me as a person. But, as I've said, that's in the past now and I'm trying to concentrate on Barcelona," he said.
"Everything that happens in the past, that needs to be forgotten. If I start thinking about everything I've gone through, I wouldn't be able to sleep."