Federer, 37, who has enjoyed a glistening career, is aiming for a 10th Halle title on Sunday, a ninth Wimbledon title and a 21st major next month.
“It’s a shame, because I am at the end of my career now, and it has gone by so quickly,” he said after reaching the final of the ATP event in Halle for the 13th time.
“That is good sign, though, because it shows that it has been enormous fun.”
“My career has been a blessing. I wouldn’t have done anything differently, apart from the mistakes I made when I was younger which we all make.”
The Swiss veteran said he was still unsure of what he would do when he finally hung up his rackets.
“My future is open. Some players need a very clear plan of what they will do ater tennis, but I don’t,” he said.
“I want to have flexibility, for my family. There will be plenty of opportunities.”
“I have my foundation, and I have various sponsors who I have been with a long time who will stay with me after my career.”