Swedish star Zlatan Ibrahimovic warned on Friday he was not back at AC Milan as a mascot but for the "last bit of adrenaline" and to lift a club he loved out of a difficult situation.
"I'm not here as a mascot to dance for the fans next to the Devil (Milan mascot)," the 38-year-old told a press conference in Milan.
"I'm looking for the last bit of adrenaline I might have. At my age, you're not looking for anything else but a challenge.
"When you're 38 and get hired by AC Milan it's something that doesn't happen very often, coming here means I still have something to give.
"I got more requests now than when I was 28," he continued.
"I am ready, I feel more than alive, I hope to play immediately."
Ibrahimovic has signed a six-month contract worth 3.5 million euros ($3.9 million) with the option for an additional year.
It will mark the Swede's second stint with Milan, seven years after he left for Paris Saint-Germain.
He played for the Rossoneri from 2010-2012 scoring 56 goals in 85 appearances and helped the club win their 18th and last league title in 2011.
One of the most successful clubs in the world the seven-time European champions are 11th in the table just seven points above relegation.
Milan chief football officer Zvonimir Boban contacted the Swede after he left Los Angeles Galaxy in October and the calls intensified after a 5-0 loss to Atalanta last month, their heaviest defeat in 21 years.
"After Atalanta, I got lots and lots of calls, it wasn't a difficult decision in the end," continued Ibrahimovic.
"Last time I left Milan I didn't want to leave. Milan gave me the happiness of playing soccer, I hope this will be true again.
"Things need to be improved in the field and that's why I'm here.
"Milan is always AC Milan and the image of ACM is something that cannot be deleted, you can't change history."
Ibrahimovic said that going to the United States after his career-threatening knee injury at Manchester United had refuelled his passion.
"After two MLS championships I feel more than lively," he said.
"It's not that I can play like when I was 28 or 35, things change but you know what you can do. Rather than running you can kick a ball from 40 metres," he smiled.
Ibrahimovic started his career at Malmo in his native Sweden.
He went on to play for Ajax, Juventus, Inter, Barcelona, Milan, PSG and Manchester United, winning trophies with all these clubs.
But Boban warned that the club would not just be counting on Ibrahimovic.
"We can't forget the horrible and unacceptable defeat at Bergamo, but we must not hide behind the broad shoulders of Zlatan Ibrahimovic," said Boban.
"We hope the course of the season will change and are optimistic about the effect he will have on the team and the environment but we need results."
AC Milan's first game after the winter break will be at home against Sampdoria on Monday.