Back in London, down the river from where he won a record eight Wimbledon titles, Federer said he had no intention of walking away from a sport he has graced for so long.
Speaking to reporters at London's O2 Arena, where Federer twice won the ATP Finals title, the Swiss was emotional at times as he explained the decision to hang up his rackets.
Asked what his plans were for the future, Federer said he would not disappear like Swedish great Bjorn Borg, who is captaining Europe against the Rest of the World this week.
"I just wanted to let the fans know I won't be a ghost. It's funny, I spoke about Bjorn Borg, he didn't return to Wimbledon for 25 years and that hurts every fan," Federer said of the 11-time major winner who quit tennis aged 26.
"But I don't think I'll be that guy. I feel tennis has given me too much. I have been around the game for too long. Have fallen in love with too many things.
"You'll see me again. In what capacity, I don't know. Still have to think about it a little bit, give myself some time."
Federer announced last Thursday that the Laver Cup, the team event he helped create, would be the last act of a professional career spanning almost a quarter of a century.
Having not played competitively since losing in the quarter-finals of Wimbledon last year, Federer will make his final bow with a doubles match, possibly alongside great rival Rafael Nadal (36).
Federer had still held out hope of making a comeback but said his knee issues had finally forced him to retire.
"My knee just doesn't allow me to play at this level anymore," he said.
"I came to realise that throughout the summer and then I was just looking for a place in time where I could call it.
"It felt very fitting for me to end my career here. Having Bjorn Borg on the bench with me when I walk out is going to be something that is beyond cool and I felt that was something really nice. Having a team behind me as well would not feel so lonely when I'm calling it a day."
Federer's 20 Grand slam titles have been surpassed by Nadal (22) and Novak Djokovic (21) in an unprecedented golden era for men's tennis. But whatever the statistics, many still regard him as the greatest player ever to wield a racket.
He claimed 103 career titles, second only to Jimmy Connors, and spent a record 237 consecutive weeks as world number one from 2004 to 2008.
His first Grand Slam title arrived in 2003 when he beat Mark Philippoussis to win Wimbledon and he went on to win it five years in a row before losing to Nadal in a 2008 classic.
